revert series if last id is deleted
[feature] drag / drop attachments fixes frappe/erpnext#2098. also fixed boo boo in revert naming series
removed allow_attach (useless) and added validation for drag and drop
[cleanup] remove allow_attach
[fix] allow_attach
[fix] removed title left
[css] sidebar
[style] default website
Merge pull request #791 from rmehta/aug-22

Revert series on delete / drag drop attachments