Merge pull request #269 from redshark1802/master

 fixed typo, wrong datatype for the option 'notString'
Minor update
Fix for an Issue #268
Update for an Issue #12
Minor update
Minor update
Minor patch for an Issue #274 (just in case to avoid this kind of problems)
Implementation for an Issue #272
Update for an Issue #272
Minor style update
Update for an Issue #278
Lowering --limit for inline query technique
Fix for an issue #279
Taking some goodies from Pull request #284
Introducing 'new style classes' (idea from Pull request #284)
Removed unused imports and variables (pyflake-ing)
Create CONTRIBUTING.md
Implementation for an Issue #283
Merge branch 'master' of github.com:sqlmapproject/sqlmap
Minor style update (capitalization of leftover class names)