The asset system and supporting libraries were using off_t instead of
off64_t to access files larger than 2GB (32-bit signed). This change
replaces all off_t with off64_t and lseek64.
There is a new utils/Compat.h added for Mac OS compatibility.
Also fixed some size-related compiler warnings.
Bug: 3205336
Change-Id: I9097b3cb7a602e811fe52f245939d8975da55e9e
Compressed assets larger than one megabyte are now decompressed on demand
rather than being decompressed in their entirety and held in memory. Reading
the data in order is relatively efficient, as is seeking forward in the stream.
Seeking backwards is supported, but requires reprocessing the compressed data
from the beginning, so is very inefficient.
In addition, the size limit on compressed assets has been eliminated.
Change-Id: I6e68247957e6c53e7e8ba70d12764695f1723bad
