config: Fix config files not reloading when only an included file changes.

The twisted logic determining if a config file should be reloaded was
mostly broken and disabled.  The incorrect test that ASTERISK-23383 fixed
actually reenabled the broken logic.  The incorrect test was causing the
timestamp to always be cleared which caused config files with includes to
always be reloaded.

* Made wildcard includes always cause a reload.  Determining if a file was
deleted cannot be determined without restructuring the cache to determine
if any files are missing from the last files actually loaded.  Also
without refactoring config_text_file_load(), the glob loop couldn't check
more than one file for changes anyway.

* Made remove the cache entry if the file no longer exists when trying to
get its timestamp or it is no longer a regular file.  This fixes the
corner case where the file was loaded, then deleted, then the config
reloaded, then the file restored with the same timestamp, and then the
config reloaded again.

* Made remove the cache entry include list when actually loading the file.
This gets rid of any stale includes the file had from the last time the
file was loaded.

ASTERISK-23683 #close
Reported by: tootai

Review: https://reviewboard.asterisk.org/r/3575/


git-svn-id: http://svn.asterisk.org/svn/asterisk/branches/1.8@415225 f38db490-d61c-443f-a65b-d21fe96a405b