Re-introduces separate Description and Instructions tab for mapper interface.

Fixes osm-tasking-manager2 issue 193. It still needs work to change the Start Contributing buttom on the Description panel to link to the Instructions pane.
The Description panel button currently does not work at all.
Duplicates project.instructions.mako as project.description.mako for working out a bug.
Changes instructions identifier to description.
Fixes the non working button on the description panel.
Finalizes new project.decription.mako page for Description tab
Restores the correct master branch main.css
Simplify gotoinstructions button wording and id
Make sure the description tab is active first
Remove duplicated project status info
Adds search by project number support to TM2 search box. fixes #160
Merge pull request #483 from bgirardot/issue160SearchByProjectNumber

Adds search by project number support to TM2 search box. fixes #160
Merge pull request #481 from pgiraud/issue193InstructionsTab

Issue193 instructions tab
Done/validated are stored as floats in db
helps avoiding falsy values for percentage in home page
Fixes #457
adding mention to wiki TM installation list
Merge pull request #489 from pgiraud/issue457

Done/validated are stored as floats in db
Merge pull request #495 from ethan-nelson/dev6

Adding TM installation list in README; re: #409