Suppress int to unsigned int cast warnings in page buffer test.
Build asymmetricfs with -Weverything when using Clang.
Use ADD_DEFINITIONS and ADD_COMPILE_OPTIONS.
Revert "Use ADD_DEFINITIONS and ADD_COMPILE_OPTIONS."

This reverts commit 47c3c1f8c9bb3d8bbb070073f6a3c20f55589b7a.

ADD_COMPILE_OPTIONS is only available since CMake 2.8.12.  Travis only has
2.8.7 available.
Revert "Build asymmetricfs with -Weverything when using Clang."

This reverts commit 79c8cf9b427166eb1263cbf78fd30d236e4bec4c.  This is due to
the CMake version issue noted in 82d4f4936229.
Fix issue when reading from the highest allocation (by offset) in a file.

lower_bound() would return end(), leading to the read being zero-filled rather
than the last chunk inspected and copied.  This issue was reported by @dannysu.
Fix issue with page_buffer::splice().

When the last whole page allocation falls on an allocation boundary, an
assertion would fail as the allocation iterator was not advanced to the next
chunk.

This issue was reported by @dannysu.
Configure memory locking.
Iteratively call vmsplice as data is flushed to the pipe.
Adjust find_block behavior when searching for allocations.
Validate overread behavior.
Reduce test case sizes to speed up Valgrind runs.
Add include for std::function.