Look at NI instead of PRI in ps output on Linux

The PRI field is the Linux kernel scheduling priority which is
different from the niceness of a process (which is what a system
adminitrator and policy-writer is likely to want to select upon). This
value is almost always larger than 20, so it isn't selectable if the
defined range per the documentation is -20,+20 anyway.
cosmetic change
Checking for ioctl() return code in GetMacAddress()
Keep loopback interfaces, closes #1112
Don't grab mac address on interfaces having IFF_LOOPBACK flag
Add GetInterfaceFlags() to get NIC flags
use yyleng instead of strlen(yytext)
Unionize range in ConstraintSyntax
First pass cleanup of utility functions in parser
Merge pull request #538 from basvandervlies/lex_use_yyleng

use yyleng instead of strlen(yytext)
Remove unused variable
Merge pull request #539 from tdlee/master

tests/acceptance/Makefile.am
Check for missing close brace '{' for body statements + 3 unit tests
Hook up promise constraint checking to parser, add syntax unit tests
small typo in commands_intro, missing "
Yr2009 is not true anymore, change to cfengine class
this is a basic example, it should run without modification
make basic examples in array section self-contained + typo
make bundle edit_line example in Pattern matching and referencing section self-contained
add file content to explain Commenting lines section