Reduce a bit the number of sections also for create directories
  Move all 'set's and 'do's to earliest as possible, to keep buildout syntax more evident
  Drop duplicated logics and 'if's reducing general code

  Use 2 different ports on apache for cached slaves, to differ http and https accesses.
  Introduce the parameter https-url (with fallback to url) to include specific https urls,
    if they are different from url.
  Include /HTTPS/ mapping to traffic server to differ the backends based on the input.

  Not all frontend clusers setup uses the same re6stnet network.

  The promise returns too much data into the PIPE, if it is the case, it makes
  the promise much much slower, causing constant timeout

Slapos.toolbox has a new dependency to pycurl, which fails to compile if libcurl cannot be found. This commit adds the component/pycurl dependency to most of the Software Releases which have a dependency to slapos.toolbox.

I tried to do it globally, so I couldn't check the compilation of all the modified SRs. Is it a way to test that all SRs still compiled ?

Also, did I forget some important SR ?

@rafael @alain.takoudjou @kazuhiko @jm 

/reviewed-on nexedi/slapos!97

forgot to update md5sum ...

so that build will not fail if the directory was left during previous
builds.

  Using ServerAliases %{SERVER_NAME} would not cause a change of URL to something
  diferent them it was requested.

because the recent version of paramiko (>= 2.0.0), that is a part of
slapos.toolbox's dependencies, depends on cryptography insead of
pycrypto.

apache-frontend: Slave with cache now have dedicated virtualhost, add checkProxyCertificate, Strip Via header option

Added:
server-alias
disable-no-cache-request
prefer-gzip-encoding-to-backend
disabled-cookie-list

SlapOS already relies on system binutils and
version 2.21.1 does not compile with recent GCC.