This acomplishes Squish Task[#17737]: Merge group by into the cogwheel
http://squish.ish.com.au/tasks/17737
Columnpicker.js and grid.js have been modified to merge the group by list into cogwheel menu.
Modified grid.js and columnpicker.js
Not to be merged untill next commit.
Using dropdown-menu and dropdown-submenu to create nested list.
Task#19949: Billing report more than seven days
http://squish.ish.com.au/tasks/19949
The dates were haywire becasue of the column header key.
They key is now set to "year day of the year".
Created a nested list for groupby options and column selector.
Made alignment and margin changes with css styling.
Added the tick mark image file.
Test cases added in this commit.
This fixes the issue of user not being able to edit milestone
eventhough he has the milestone edit permission
http://squish.ish.com.au/tasks/20051
The equality condition in test case has been modified in this commit.
Test cases for a non-admin user editing milestones
with only milestone edit permission.
Merge pull request #489 from ari/viks-widget-shows-oldest-task

Test cases added in this commit.
Merge pull request #497 from ari/viks-user-can-not-edit-milestone-even-when-permitted

This fixes the issue of user not being able to edit milestone
The cogwheel menu now appears on clicking the icon and disappears
when the mouse is moved out as it originally was designed.
This fixes ducplicate tab name "Current projects" instead of "Completed projects"
https://github.com/ari/jobsworth/issues/491
Edited the tab name in views/customers/edit.html.erb
EmailsController test cases were failing due to fixed date in the email message.
Changed the message file to .msg.erb and using the present DateTime.
Removed the warbler gem from development group in the Gemfile and
added it to assets group.
Removed warbler out of all groups
Merge pull request #505 from ari/viks-user-can-not-edit-milestone-even-when-permitted

Placing the warbler gem in a different group
Modified the mail message