Rust Web Server

Change list:

• Fixed typo in command-line argument cors-allow-methods (previously was 'cors-allow_methods')
• Changed the name of the argument to thread-count to be consistent with the config file (previously 'threads' as an argument and 'thread-count' in the config file).
• Removed dependency used to parse config file with the handwritten module. As a result smaller final executable size and faster build time.