Split out parsing and expression trees from regexp.y

Start of splitting regexp.y into logical components instead of the mess
it is today.  Split out the expr-tree and parsing components from regexp.y
int expr-tree.x and parse.y and since regexp.y no longer does parsing
rename it to hfa.cc

Some code cleanups snuck their way into this patch and since I am to
lazy to redo it, I have left them in.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-By: Steve Beattie <sbeattie@ubuntu.com>

parser/libapparmor_re/apparmor_re.h

@@ -10,6 +10,8 @@
 #ifndef APPARMOR_RE_H
 #define APPARMOR_RE_H
 
+#include <stdint.h>
+
 typedef enum dfaflags {
   DFA_CONTROL_EQUIV =		1 << 0,
   DFA_CONTROL_TREE_NORMAL =	1 << 1,