Update some links in the User Manual
Add a link to instructions for setting up a Visual Studio development environment
Fix regression in evaluating composite columns that use other composite columns.

Assume column X uses column Y. If X assigns to template variables then evaluated Y, the variables were cleared. The regression happened because the performance increase changes to use ProxyMetadata also caused X and Y to be evaluated in the same formatter instance where before they were evaluated in separate instances. This triggered a long-standing latent bug where a 'global' local variable dictionary was cleared every time a template was executed. The fix is to make the local variable dict local to the template evaluation instance.
Merge branch 'master' of https://github.com/cbhaley/calibre
Update Nikkei News
Start work on function mode for S&R in the editor
Add function mode support to the saved searches dialog
More builtin search and replace functions
Add saved searches context menu items to the functions box
Tooltips for function mode controls
Move imports out of S&R builtin funcs
DRYer