Added missed tests for wallet index page.
[#25] Added column with information about remaining amount of each wallet on wallet index page. Closed #25
[#25] Corrected test for checking row in table.
Merge pull request #38 from smt116/25-remaining-money-in-each-wallet-on-wallets-index-page

[#25] Added column with information about remaining amount of each wallet on wallet index page.
Fixed bug with incorrect sorting by 'tablesorter.js' plugin.
Merge pull request #40 from cintrzyk/master

Fixed #30 issue. Added ability to sort text with polish chars.
 Added approval for expenses (allow user to mark which are already done). Closed #15.