Include stdint.h for uint64_t. Also remove a redundant return at the
end of a function.

Bug: None
Test: make
Change-Id: I7712bd8020bc063463f5fee09fa05439b462cfac

The Makefile didn't build libbspatch and libbsdiff. This patch includes
those libraries in the Makefile and moves the header files exposed by
those to an include/bsdiff subdirectory following the Android
convention so calling program can include "bsdiff/bspatch.h" avoiding
any collision with other libraries.

The Android.mk is updated to export the new include path while keeping
the old style until calling programs are updated.

The new Makefile allows Chromium OS to build the new libraries.

Bug: None
Test: FEATURES=test emerge-link bsdiff; sudo emerge bsdiff
Test: mmma external/bsdiff

Change-Id: I2ea9251eb224e9418fe236e4c4c9c5621853f590

If current position is not the beginning of a extent, it will read past
current extent length.

Bug: 24478450
Change-Id: I53e4f3e8257e80732280e68647ec89b5b604c3a3
TEST: Added a unittest.

Implemented a method to get the size of the FileInterface object
directly.

Bug: 24478450
Change-Id: I9aab80b33cc554551ce79bfee52e94e8e04775db
Test: make all test && ./unittest

This patch moves the exfile.cc implementation to a C++ class with an
abstract interface of a file. The implementation of exfile.cc, renamed
to extents_file.cc, now uses C++ STL classes and has unittests to test
its core functionality.

Bug: 24478450
Test: Unittests added. make all test -j5 && ./unittests

Change-Id: I8d8f07150ad2ea465c55b5178ca9fbab49185eea