Initial commit for issue #6.

This check-in adds the critical skeleton to supply emails (along with invite.ics files) when the meeting is updated.
additional views are being added for update emails.
Currently the entire path for meeting_add and meeting_update is completely saperate.
Provide email notificiation for updates and cancellations of meeting.

This is a major work towards email notifications under updates.

* Now updates will have proper emails with meeting invites.
* This will provide 'SEQUENCE' number in invite so if the meeting keeps updated, it will be reflected as same meeting in the calender revised rather than yet another meeting. (Without this, meeting updates were treated as new meeting and flood the calender)
* Added notes and change details will be highlighted.
* Cancellation of meeting is handled. The calender will also recognize this as cancellations
* Few minor changes - time display in meeting's mail is improved.

Major code changes have take.
* Earlier check-ins had meeting_add and meeting_update functions are now removed and they are replaced by meeting_save
* mailer patch is now called after_save both for newly created record as well as updated record.
   > this was essential because after_update was getting called 'before' the create_journal and hence there was no way to add journal notes as part of the email.
   > now meeting_save is called after create_journal and hence updates are proper.
* by replacing meeting_add and meeting_update to meeting_save we have also updated (removed/renamed) respective view files
* common meeting_save function saves a lot of code as well.
* There is a function used for creating all journal entries into a hash of strings. This is in part some duplication of a similar function in meetings helper but somehow I was unable to include all stuff from mailer patch.
* Works for text or HTML emails.
* Provide URL for attachments in emails.
Merge pull request #10 from dipanm/master

Pull request for Issue #6 - Email Invites for update and cancellation of mails.