rule_engine: Check that only a single external module claims a rule, and report as an error any subsequent rule module claiming ownership of a rule.
build: Prioritize Lua headers in libs directory over any system Lua headers. (See below)

Before this commit there was a problem if Lua was installed in a non-standard location.  In that case, the build would add -I flags to AM_CPPFLAGS to find those non-standard header files (e.g., for boost) but this would cause the Lua header files there to be used instead of the ones in the source tree.  This commit rearranges Makefiles to move the local -I before any added by the configure script.
ironbee/waggle/signature.lua: Setting a stream field sets phase automatically.
config.lua: Adding 'capture' and 't' rule modifers defined in modules/rule.c.
config.lua: Fixing target name to not include transformations.
config.lua: Cleaning up previous commit. target_name was a duplicate of name.
engine/var: Relax requirements on name lifetime in ib_var_source_acquire().  (RNS-524)
engine/module: Warn if loading a module for a different IronBee version; error if loading a module for a different IronBee ABI.
waggle: Adding unit test to check that transformations do not cause errors.
engine: Remove engine_init as its use is very small and illdefined.
xrules: Fixing regex error that cause the action to include the argument.
xrules: Fixing assert failure caused by actions being swapped, not assigned.
xrules: Minor fix - ScaleThreat object should be named correctly.
xrule: Bug fix in path comparison. The string compare operator works returns 0 when one string is too short to be compared fully. The previous code assumed strings too short to compare would be considered less-than the longer string.
xrules: Move header rules to earlier phase (before rule engine).
core: Move generating field values to earlier hooks.
core,modules: Use handle_context_tx instead of request_header_finished as we need a context.

Conflicts:
	modules/user_agent.c
xrules: For allow, unset ALL blocking flags and SET the allow flag.