Start printing out excel sheets in XML rather than html tables.

Consolidated periods#list, groups#list and teams#list into
assignments/list(.html|.xml). This file sets the xml separators and
prints out assignments/_list_data.xml.

NOTE: Still need to add this feature for reports. It is broken
currently.
Close #25. Finish converting xls to xml.

Also sorting reports by date, not reverse date, on assignments#show
Merge branch 'excel'
Bugfixes for groups#list and teams#list
Bugfix in assignments/_list_data.xml

In order for Microsoft Excel to recognize the xml document, the document
must be fully properly formatted. Furthermore, in order for things to
display correctly, you can't leave any space around number in cells.
Enable deletion of assignments. Issue #33.

Only for !period.keep_updated? periods.
TODO: Enable for updated periods as well?
Enable editing of assignment.status for non-updated periods. Issue #33.
Merge branch 'master' into delete_assignments

Need to use @list_type that gets set in upstream master branch.
Enable display of all assignments for a period - including inactive ones.

Also add a display_all checkbox to list/_form that selects all/none of
the report fields.
Close #35. Update button colors on users#show
Fix #37. Run validations on pledges before saving.
Add admin tool to view an individual's user page.
Close #34. Fix issues with lists.

Link to reports from assignments#list and reports#list.
Only link to groups and teams if the @cas_user has permission.
Don't display 0 values when they should be nil. e.g. when a goal has not
been assigned.
Don't give the option to view goals that don't exist on reports#list.
Close #36. Add more flexibility to report field ordering.

Now, you can choose to put a field before the goal_lines. And, the
mechanism for setting the list indices is much prettier in the backend.
Close #39. Add more fields to lists.

Add combined percentages for inhand, pledged and total.
Add percentage for each goal for total.
Fixed report_field_line validations so they don't run twice and they
allow nil non-required numeric fields.
Added a delete button for on reports#show as well as assignments#show.
Issue #38. Finally addressing missing .png errors

Did this really fix the problem? Have to see it in production.
Also added the Cru favicon.
Also added the airbrake javascript notifier to see if that gives me
anything.
Close #40. Add number of partners to reports.

- Implement by adding report_partners_lines table
- Add a stub for report_partners_line.new as well as
report_partners_line.total, which is the only field used right now.
- Fix display issues with error fields and appended bootstrap fields.
Close #41. Add user's account_number and phone to assignments#show.
Bugfix in assignments#list_data
Fix various display bugs for form errors