Merge pull request #173 from aseemmittal/dirty

Bill revised and receipt generated
Resgisters extended. More constraints added.
Merge pull request #174 from jasvir99/dirty

Resgisters extended. More constraints added.
listing of products modified.
Merge pull request #175 from jasvir99/dirty

listing of products modified.
tinymce added so that use can have custom headers of bills.
Merge pull request #176 from jasvir99/dirty

tinymce added so that user can have custom headers of bills.