Implemented issue #37 remove and purge command .

Signed-off-by: Rack Lin <racklin@gmail.com>
Merge pull request #46 from racklin/enhancement/remove_purge

Implemented issue #37 remove and purge command .
Added -variant to disable php feature.

Signed-off-by: Rack Lin <racklin@gmail.com>
Merge pull request #47 from racklin/disable_variants

Added -variant to disable php feature.
merged disables and disable properties to disable property.

Signed-off-by: Rack Lin <racklin@gmail.com>
Merge pull request #48 from racklin/disable_variants

Merged disables and disable properties to disable property.
Fixed #51 EnvCommand display and save error messages to init file bug if version and PHPBREW_PHP env not exists.

Signed-off-by: Rack Lin <racklin@gmail.com>
Merge pull request #52 from racklin/bugfix/51

Fixed #51 EnvCommand display and save error messages to init file bug
release 1.6.5
Update src/PhpBrew/Command/SelfUpdateCommand.php

Self update automatically reinitializes phpbrew
Add icu variants
Add icu variants
Merge branch 'master' of git.corneltek.com:php/PHPBrew
recompile phpbrew
Importing task class files
the url downloader should only returns the basename of the url
update doc block
remove logger object dependency from UrlDownloader
improve svn downloader
let download task works