Speed up tibb build
Speed up tibb build

[Description]
The Titanium Mobile Platform Development doc says to use NUM_CPUS to parallelize the build so now that env var is utilized.

[Changes]
tibb/Makefile
- added J_OPTION to make commands to use NUM_CPUS if available, or 1 if not

[Tests]
Test 1: Build tibb
1) Set NUM_CPUS env var to the maximum number of supported cpu threads
2) In tibb directory, run make all
3) Verify the j option is passed to the target's make command

appcelerator/titanium_mobile_blackberry,appcelerator/titanium_mobile_blackberry,appcelerator/titanium_mobile_blackberry,appcelerator/titanium_mobile_blackberry,appcelerator/titanium_mobile_blackberry,appcelerator/titanium_mobile_blackberry