client: use struct stat member tests for time

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>
pipe: avoid conflict with Pipe.cc on case-insensitive fs

pipe.c and Pipe.cc produce the same intermediate file names on
case-insensitive file systems (like HFS). This renames pipe.c/pipe.h in
order to avoid the conflict.

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>
autoconf: search for uuid_parse in system libs

AC_SEARCH_LIBS will first try to resolve uuid_parse in the system
libraries (OSX), and then will try other libraries (e.g. libuuid). The
$LIBS variable will be updated with the result, so we don't need an
explicit -luuid in src/Makefile.am.

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>
autoconf: search for -mt version of boost_program_options

The -mt version of the boost libraries shows up in OSX. Other boost
libraries were searching for the same alternative. Adds lib to LIBS to
avoid explicit -l in Makefile.am.

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>
log: remove unused lock

m_lock is initialized and destroyed, but never used.

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>
code_env: do not use prctl on non-linux

get_process_name is platform specific. Check for Linux prctl function
and headers, and add reference to the relevant OSX function.

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>
blkdev: support blkdev size query on osx

Support OSX, add checks for platform specific headers, and remove some
unused headers.

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>
utime: use to_timespec for conversion

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>
wbthrottle: use posix_fadvise if available

Only adding information about data usage. This won't effect correctness;
finding analagous techniques on other platforms woudld be useful for
performance.

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>
context: handle platform without sem_timedwait

On OSX sem_timedwait is not available. This patch simply turns off the
heartbeat interval feature. Building a replacement should be possible, but
is needs some careful thought because pthread mutex/conds aren't thread
safe, and sem_post is called from SIGHUP.

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>