* replace require function calls with stndse.silent_require
* fixed a bug in nse_main that would fail creating scripts.db when a script
fails to load
* reworked some code to provide limited functionality even though SSL is not
present
providing common code for "Simple Authentication and Security Layer" to
services supporting it. The algorithms supported by the library are:
PLAIN, CRAM-MD5, DIGEST-MD5 and NTLM. [Patrik Karlsson, Djalal Harouni]