Use cache to  save some promise instance information.
First run of slapgrid fill each promise cached (when there is no cache). The next run will check some usefull info like if promise `is test less` or promise `is anomaly less` directly from cache without need to import the module.

Cache is updated if promise file or module change, or if the promise periodicity expire (when the promise it update cache).

/reviewed-on !101

- Round tax comparation, else we hit floating point impression.
- Free trial user is defined by ERP5 Login reference and not Person Reference.

Simple subscription Case
Request three instances (ie.: 3 VMs) Case
Two concurrent Subscriptions Case

If the first 3 months are payed, the subscription request is confirmed (allowing allocation).

When causality is set and it is a Subscription Request, do not aggregate services (it will generate individual inviduals invoices per Subscription).

When a user has multiple requests, it should not merge, and it should generate 1 invoice per subscription request.

slapos_accounting: Use specific trade condition if Hosting Subscription comes from a Subscription Request

This allow the system differ the 2 scenarios.

When the Hosting Subscription comes from a Subscription Request, the Trade Condition applied is a different one (slapos_aggregated_subscription_trade_condition).

Update all related scripts to work accordinally.

SPL on this case are started as soon they are created and a payment generated.

This is used for subscription mode, like rapid.space VM-Like services.

Subscription and Trial uses setDefaultEmailText when create a Trial/Subscription as annonymous which will trigger this workflow and raise Unauthorized when invoke Coordinate_beforeCoordinateTextChange.

As Reacheability/Unreacheability is not tracked on SlapOS master for now, so this commits remove the interaction workflow for Email (only).

Code migrated from testSlapOSERP5DefaultScenario.

This would guarantee that the ungenerated payment from others tests are generated, while you are running live tests.

/reviewed-on !99

This fixes a regression introduced in commit 7467ef4c
("Add Python 3 support").

/reviewed-on !98

The reload part is mainly used for tests, module is reloaded if the promise file has changed. Here, __file__ ends with pyc when promise_path ends with py.

Since the compatibility with python3 the code change to not encode the string anymore.

@jm @bminusl can you take a look if it is enough (I will improve commit message after)

This at least make the test pass.

/reviewed-on nexedi/slapos.core!94

Just like reference implementation support empty keys.

/cc @rafael 

This makes slapproxy behave the same way as SlapOS Master for empty keys while requesting slaves.

/reviewed-on nexedi/slapos.core!96

There is now `EmptyResult` object which is an empty promise result. This result is send if the promise test or anomaly was skiped (if disabled).
To prevent raise because `EmptyResult` is unknonwn on old slapos-node with `slapos.core < 1.4.17` we will send an empty TestResult instead.

Support for promise test-less or anomaly-less allow to disable either the test phase or the anomaly phase.

by default, test and anomaly are enabled, `__is_tested = True` and `__is_anomaly_detected = True`. Test will run when buildout is processing the computer partition, and anomaly when the partition is processed.

Call `self.setTestLess()` in `__init__.py` of the promise will disable Test and set `__is_tested = False`. Call `self.setAnomalyLess()` will rather disable Anomaly and set `__is_anomaly_detected = False`.


    def __init__(self, config):
        GenericPromise.__init__(self, config)
        # Skip test check on this promise
        self.setTestLess()

If the promise is test less, then slapgrid will not run the promise while processing the partition which mean that the promise will not report error, only Anomaly will be checked. Samething, if promise is anomaly less, only test will run when slapgrid is processing the partition.

/reviewed-on nexedi/slapos.core!93

Support for promise test-less or anomaly-less allow to disable either the test phase or the anomaly phase.

by default, test and anomaly are enabled. Test will run when buildout is processing the computer partition, and anomaly when the partition is processed.

Call `self.setTestLess()` in __init__.py of the promise will disable Test and set `__is_tested = False`. Call `self.setAnomalyLess()` will rather disable Anomaly and set `__is_anomaly_detected = False`.

If the promise is test less, then slapgrid will not run the promise while processing the partition which mean that the promise will not report error, only Anomaly will be checked. Samething, if promise is anomaly less, only test will run when slapgrid is processing the partition.