Added a cache management system for pre-processed PNG files
along with unit tests. The cache system will be used if
the --no-crunch flag is passed to AAPT during the package
phase. The cache can be updated by a call to 'aapt crunch'
(see usage statement). Also put in benchmarking code.
Change-Id: I58271fb2ee2f5f9075fd74d4ff6f15e7afabd05c
This adds -lpthread on linux for aapt and localize, which appear to be
needed on some linux distros.
Signed-off-by: Jean-Baptiste Queru <jbq@google.com>
