Code quality improved and working tree cleaned.

Since now we are using JQueryMobile 1.4.3, JQueryMobile 1.4.2 files are cleaned from the working tree.

Moreover, client/www/index.html file is changed. Changes for improving code quality:

  - Instead of using different SQL error methods, only one parameterized SQL error function used.
  - Functions are written for some procedures to improve readability of the code.
  - Function explaining comments are added.
  - Also some logical changes on the code.(e.g. where to load contacts, ...)