Added pecl installer for building php extensions

Fix: Accidentally switched logic in if construct

Support creation of ini file to load extension

Moved logic from process to initialize

Added documentation on options and re-use push_text

Use file rather than push_text - Doesn't work at the moment

Use sudo for file transfer, unless explicitly told not to

Added tests for pecl installer

Add test for passing string as argument to ini_file

tidied duplicate code up a bit
Merge pull request #153 from troelskn/feature-add-pecl-installer

Added pecl installer for building php extensions