Added Query functions

Added sqliteexecute function which retrieves the data from the database
removed swap files created by vim
tuned it a bit using splat operator
tuned it a bit using splat operator
Amended the file to describe the changes
tuned it a bit using splat operator
Added custom exception,crated separate test file, handled uninitalized database
renamed test_select to test_execute, added couple of more test cases
Describes new functions
Merge branch 'master' of github.com:shyamperi/scraperwiki-ruby
Factor out repeated @db opening code into a shared function