[Coding style] fix indention
Improve doxygen comments
Fix macros for version output

- Authors in alphabetic order
- Free Software Foundation doesn't hold the copyright
Fix GPL boilerplate in fg_argparser.[c|h]
Fix compilation issue on FreeBSD

src/fg_pcap.c: In function 'fg_pcap_work':
src/fg_pcap.c:295: error: label at end of compound statement
*** [src/flowgrindd-fg_pcap.o] Error code 1

The label should point to a statement. C mandates this:

(C99, 6.8.1 Labeled statements p4) " Any statement may be preceded by a
prefix that declares an identifier as a label name."
Unified parsing using macro "PARSE_ERR"
Fix possible unconditional comma issue in PARSE_ERR macro
Use ifdef to prevent that header will be included twice
Include config.h in fg_list.[c|h]
[Coding style] use braces for 'else' statement

If an 'if' condition is not a single statement, other branches should
uses braces too.
[Coding style] Apply C99 standard

Declare int variable in for block