Merge pull request #247 from dshrader/master

spec file updated to not create and remove default PLFS mount points and backends.
fix a concurrency problem with mlog when using the PLFS native API.
mlog_filter() uses mlog_xst.mlog_facs if mlog_xst.tag is set, but
there is a window of time where mlog_open() was setting mlog_xst.tag
before mlog_xst.mlog_facs was init'd.   attempt to close that window.
consider converting mlog lock to PTHREAD_MUTEX_INITIALIZER in the
future.

issue #246.
reported by Jingwang and Zhenhua via John Bent
Merge pull request #248 from chuckcranor/mlogfix

fix a concurrency problem with mlog when using the PLFS native API.
deleted old plfsrc and spec files + their instructions as things have changed. Also added mpich2 to .gitignore
Merge pull request #252 from agtorre/master

Cleanup for 2.4
fixed a build error due to an unused variable breaking the build since our coding standard
is to ensure building with -Werror,-Wunused-variable
Merge pull request #253 from johnbent/master

Fixed build error.
fixed a performance issue where if the user did plfs_open with both
O_CREAT and O_TRUNC, the container_open called both
container_create, which did a truncate, and it also called
container_truncate, which did it again

One fix would have been to not truncate in container_create and only
truncate in container_truncate but it's a bit more efficient to do
the truncate in container_create when possible.

So we fixed this by just not calling the container_truncate when we
realize the the container_create already did the truncate for us.
added a comment
Merge pull request #254 from johnbent/master

Fixed where code was doing truncate twice
fixed a bunch of warnings found using a new compiler, mostly uninitalized variables and comparing signed to unsigned variables. Also fixed the build process for static plfs -- it now links with static yaml
Merge pull request #255 from agtorre/master

Compiler warning + static build
Reduce memory pressure with large indexes
Removed build warnings for shadowed types
Merge pull request #257 from thewacokid/master

Open indexes in shared mode to reduce memory usage
Exclusive create support in container mode

add O_EXCL for create opeartion if necessary
check O_EXCL flag before O_TRUNC

issue #249.
Merge pull request #259 from ZhangZhenhua/o_excl

Exclusive create support in container mode
Update CMakeLists.txt and Changelog for tagging 2.4rc3.