Enable -std=c99 and -pedantic.

Standardize PVFS_sys_layout.

Move PVFS_sys_layout encode and decode to the header and use standard
encdecode functions.

Remove support for custom static initializers. They are glibc specific.

Use quicklist for NCAC.
Set _XOPEN_SOURCE for flex. Do not set __STDC_VERSION__.

Setting __STDC_VERSION__ should never be done. Figure out which flag the
compiler needs and pass it. C99 mode is used now and flex does not
report any errors.

Use _XOPEN_SOURCE to get strdup.
Remove unnecessary references to malloc.h.

Malloc and friends have been in stdlib.h for at least a quarter of a
century now.
Need to explicitly cast between different enum types.
Fix PINT queue bugs caught by OS X.
Fix empty if statement.
Modernize configure.ac.
Use POSIX getgroups function.
More efficient byteswapping.
Add ull to large integer constant.
Calloc should zero memory.
Remove extra checks from decode_malloc.

C already defines malloc(0).
Miscellaneous fixes from analysis.
Remove dead code in tcache.
Check for error conditions.
Fix error code that never got returned.
Remove code that is dead if a system constant is not defined.
Fix buffer size check that is never used.
Fix error in usrint initialization code.
Fix memory leak when a credential is decoded.