Bullet-proof the lseek/read in Inflater.setFileInput.

Also document why that non-API method exists, and that we don't have
benchmarks to support the claimed optimization.

Also be more consistent about setting LOG_TAG, and fix a few old-school
copyright headers.

Change-Id: If9fdc4583eaf91275ed44e2dc56174819d1913d0
20 files changed