Fix --enable-debug regression while still enabling overridable CFLAGS.

AC_PROG_CC sets some default values for CFLAGS on some systems, so
we need to separate between those, and flags that are passed in from
the command line.
Leak-fix: delete the list passed to FnCallNew().

FnCallNew makes its own copy of the list it's passed, and the parser's
original is no longer needed, so the parser should tidy it away.  I'd
previously cleared it, but hadn't realised we still owned it !

2394 blocks definitely leaked, 57k directly plus 123k indirectly.
Leak-fix: GenericAgentConfigDestroy() neglected two members.

The original_input_file and input_dir were first cleared away and then
set by GenericAgentConfigSetInputFile() but weren't being released at
the end of the object's life-time.
Leak-fix: handing off ownership to AppendItem(), which makes its own copy.

AddOpenPorts() called StringWriterClose() and passed the result in to
AppendItem(), which doesn't take over ownership; so it was leaked.
Use StringWriterData() instead and do a simple WriterClose() after.
Leak-fix: MonitorStartServer() neglected to yield a lock it had acquired.

So, naturally, it leaked thislock.lock.
PolicyAppendBundle(): constify its Rlist *args.
Skip the unused FnCallDatatype (using #if-ery).
Merge pull request #1405 from kacfengine/overridable_CFLAGS

Fix --enable-debug regression while still enabling overridable CFLAGS.
Merge pull request #1406 from ediosyncratic/leak-fixes

A few more leak fixes
Change csv_parser max size to 4kb

csv parser is based on static buffers, and I want it to be aligned
with CF_BUFSIZE but didn't want to introduce cf3.defs.h as dependency,
so I used a number.

This should be based on malloc and not on static buffer but don't have
time at the moment to make bigger change.
Make use of preprocessor macros for static known_dirs.c functions
rename MAX_WORKDIR_LENGTH macro to more generic MAX_DIR_LENGTH