Fix set but not used error.
Adding PersistDirMode and PersistFileMode directives.

 - Adding ib_context_t to necessary persistence module calls.
 - Adding mode_t for files and directories to persist.c module.
 - Removing unused list in said persist.c module configuration.
 - Adding code to look up module configuration and use fmode and dmode
   values.
 - Defaulting values to 755 for directories and 644 for files.
 - NOTE: Only the global configuration context may functionally be used
   as persistence module configuration seems to happen in the root
   context only. (?)
Updates to installation and RPM packaging.

* An empty ironbee.conf is now installed as /etc/ironbee/ironbee.conf.
* The ironbee-trafficserver RPM adds the ironbee plugin configuration to
  trafficserver's plugin.config file when installing.
config.c: Simplify file parsing so that we don't have to strdup() for each file block we process
docs: Document libinjection based transformation and operator.
docs: Document SQL transformation.
docs: Alphabetize operators.