Various minor improvements and bugfixes.
- Adds the '!=' operator.
- Fixes several major parser bugs which caused incorrect parses.
- Fixed the implementation of some operators like 'or' and 'and'.
- Improve table layout (now includes thead/tbody).
- Render "query returned 0 results" for queries that returned no
results. - Catch more errors at runtime and display them inline instead of just in the console.
- Specify a default value for nulls.
- Mild README comprehension improvements.
- Added donation option and contributor section to README.