Added delete feed feature. Minor fixes.

Added delete feed feature which includes SQL, PHP and javascript
functions. Corrected minor code-smells (changed some == to ===).
Corrected calling ajax with inline data. Added html5 attribute data-id
to each feed. Added javascript utility functions to remove feeds.
Code refactoring.

Changed javascript loading to the end of HTML (no need for
onDocumentReady ...).
Changed overall structure of js file. Now there is a static variable
called tchiRSS which contains all the information.
Merge pull request #1 from jsvgoncalves/master

Added delete feed feature. Minor fixes.