res_sorcery_astdb.c: Fix regex handling and keep simple prefix matching performance.

The sorcery astDB wizzard does not handle regex correctly if the pattern
begins with an anchor character.

This patch attempts to convert the anchored regex pattern to a prefix
pattern supported by astDB for performance reasons.  If it is not able to
convert the pattern it falls back to getting all astDB members of the
family and doing a normal regex pattern matching on the retrieved records.

Review: https://reviewboard.asterisk.org/r/3161/


git-svn-id: http://svn.asterisk.org/svn/asterisk/branches/12@408385 f38db490-d61c-443f-a65b-d21fe96a405b
config: Add file size and nanosecond resolution fields to the cached modified config file information.

Repeatedly modifying config files and reloading too fast sometimes fails
to reload the configuration because the cached modification timestamp has
one second resolution.

* Added file size and nanosecond resolution fields to the cached config
file modification timestamp information.  Now if the file size changes or
the file system supports nanosecond resolution the modified file has a
better chance of being detected for reload.

* Added a missing unlock in an off-nominal code path.

(closes issue AST-1303)

Review: https://reviewboard.asterisk.org/r/3235/
........

Merged revisions 408387 from http://svn.asterisk.org/svn/asterisk/branches/1.8
........

Merged revisions 408388 from http://svn.asterisk.org/svn/asterisk/branches/11


git-svn-id: http://svn.asterisk.org/svn/asterisk/branches/12@408389 f38db490-d61c-443f-a65b-d21fe96a405b