Update git to 2.13.0

Update pcre to 8.40 and optimized for size.

Update make to 4.2

update m4 to 1.4.18

Add source compile and check methods

add check method

(UPDATE) Remove python34 & replace with python3

Fix bz2.rb to solve several problems

update libxml2 to 2.9.4

Update libssh2 to 1.8.0

Update curl to 7.54.0

Update expat to 2.2.0

change method names to conform to ruby style guidelines

Change to not install static library.
Change to strip binaries and libraries.

Add compile methods
Correct dependencies

Add source compile methods

Add source compile methods

add check methods

Add source compile methods

Add check method
Correct the version number
Correct dependencies

Support "depends_on name => :build" style dependencies

Change to abort if no precompiled binary nor source is available

Change to not create static libraries for several packages

Update bc to 1.07.1 and add new related packages

change to use readline library