Fix STANDBYMODE keybinding so that it really only takes effect in the main menu and not any sub-menus.
Add 'next recording' information and 'Recording conflict' warning to standby screen.
When the backend is idle and counting down to shutdown, the time remaining is now also shown on the standby screen.
Delete duplicate recording rules before adding unique index.

Commit af5836e9 added a unique index to the record table to prevent
the creation of duplicate recording rules, primarly from the internal
web interface or mythweb.  However, some users had already created
duplicate rules which caused the index creation to fail.  This commit
changes the update to delete the duplicate rules before creating the
index.
Added check to frontend startup to enter standby mode immediately if an automatic start was detected.
This basically involves checking the following:

*  Is a backend also running on the same machine?
*  If it's the master backend, is the current time close to the wake-up time?
*  If it's a slave backend that is set up to be woken automatically, is the current time close to start time of the next recording scheduled for this host?
Fix FFmpeg Build for win32/msvc
Add missing include.