fix: Changed the name of the script from sencha-bridge to sencha.
This helped fix a problem when used in combination with the
Sencha Cordova Builder. Instead of defining an alias, it now will
place its directory in the system PATH, thereby taking over the
sencha command.

feature: When used with the Sencha Cordova Builder, this script will
automatically delete the temporary build flag files used to kick off
the build process. This eliminates the remaining manual steps that
the Sencha Cordova Builder required.