pfSense

Clean up this code a little.

Use different logic for this function, copied from crypt_acb.php. Ticket #537

Add pfSense_BUILDER_BINARIES: and pfSense_MODULE: additions

• Add run_plugins() function
• Use run_plugins() function in filter.inc
• Add plugin hook for parse_config and write_config

Add support for export and import of encrypted configuration files. A set
of command line utilities for encypting and decrypting the files format
is available from the tools/config-crypto directory.