binpac: Adding a new binpac::init() function that must be called by the host

before anything else.

Internally, this function compiles all regular expressions, avoiding
to that inside the regexp constructore. The code is a bit hackish due
to the way the regexp code depends on the Bro header.

tools/binpac/lib/binpac_regex.cc

@@ -0,0 +1,10 @@
+
+#include <vector>
+
+class RE_Matcher;
+
+namespace binpac {
+
+std::vector<RE_Matcher*>* uncompiled_re_matchers = 0;
+
+}