Multiple changes

Refactor logging
- Webscraping class very verbosely logs, push those logs into webscraping.log
- Add debug and info logging to screenshot model and view handler

Enhance handling of arguments
- Default arguments are provided for all possible arguments except for the submitted
  html document
- Gross arguments are overwritten with default values where sensical

Enhance functionality
- support for minimum image width/height added
- support for png screenshots is added through format argument
- support for altering jpeg quality is added through quality argument
- 400 http return code returned on request parsing related errors