+ metadata class to the model
+ selection of the main currency during registration
moded ENABLED field from userDetails to Metadata class
issue close #43
changed icon
temporal commit
+ addition of a new category. Parent selection is not yet working.
+ category selection for transactions on creation
fixed transaction deletion jsp form
issue close #46 
slight clean up
unique constraint to user_details.user_username added
Merge branch 'development' of https://github.com/DmitryZakharov/homeBudgetWeb into feature/issue_48

Conflicts:
	HomeBudgetWeb/src/main/java/org/homebudget/controllers/TransactionController.java
	HomeBudgetWeb/src/main/java/org/homebudget/services/UserManagementService.java
	HomeBudgetWeb/src/main/webapp/WEB-INF/views/transaction.jsp
	HomeBudgetWeb/src/main/webapp/WEB-INF/views/transactionDetails.jsp
#48 Merge. Conflict resolving
Merge branch 'feature/issue_48' of https://github.com/DmitryZakharov/homeBudgetWeb into feature/issue_48

Conflicts:
	HomeBudgetWeb/src/main/java/org/homebudget/controllers/UserManagementController.java
tests are not running