refactored launcher API and implemented PEX extension point for composer launcher
Merge branch 'develop' of github.com:pulse00/Composer-Eclipse-Plugin into develop

Conflicts:
	com.dubture.composer.core/src/com/dubture/composer/core/launch/environment/EnvironmentFactory.java
	com.dubture.composer.ui/src/com/dubture/composer/ui/wizard/project/ComposerProjectWizardSecondPage.java
added autocompletion to composer project wizard, fixed launchManager