[TIMOB-15839] [TIMOB-15820] [TIMOB-15841] [TIMOB-15857] [TIMOB-15860] [TIMOB-15879] Android build bug fixes

[TIMOB-15839] Fixed bug with error checking titanium_prep.

[TIMOB-15820] Fixed crash when attempting to create a temp folder with a missing parent folder.

[TIMOB-15841] Added better sdcard ready checking and error reporting.

[TIMOB-15857] Fixed crash when repeatedly building an Alloy app for device, emulator, device, emulator, etc where files were trying to be deleted twice.

[TIMOB-15860] Fixed bug with relative js files referenced from html files were not being converted to relative urls wrt the resources dir.

[TIMOB-15879] Fixed bug with how image resource filenames are hashed.