Initial cache implementation [MIFOSX-259]

This pull request contains the initial phase of distribute caching project. I have attached link to an excel file which contains a summary of the cached methods.

All the methods cached here are not suffer from any of the issues mentioned in "challenges" section in the wiki page

Excel file : https://www.dropbox.com/s/4lvxkdvvs0npwwg/cache%20%20analysis%202.xlsx

Project Wiki page : https://mifosforge.jira.com/wiki/display/RES/GSOC+2013+-+Distributed+Caching+support

Jira issue : https://mifosforge.jira.com/browse/MIFOSX-259