ENYO-3343: remove the xml tag <gap:platforms>.
ENYO-3343: add the comment "Platforms" before <gap:platform>in the config.xml file.
ENYO-3343: Merge remote-tracking branch 'origin/master' into ENYO-3343
Merge pull request #625 from enyojs/ENYO-3343

ENYO-3343: Allow the selection of a target platform to build a Phonegap application.