This patch also updates the MidiDemo to automatically refresh the device
lists when the set of available devices changes.

This is a breaking change - see BREAKING-CHANGES.txt

Co-authored-by: Roland Rabien <figbug@gmail.com>

Changed the lifetime of the default MIDI oputput.
Removed the need for Timer workaround in AudioDeviceSelectorComponent.

This commit removes the various compiler-specific JUCE_DEPRECATED macros and replaces them with C++14's deprecated attribute. It also removes the JUCE_CATCH_DEPRECATED_CODE_MISUSE flag as we can rely on the override specifier catching usage of these old virtual methods, and tidies up the DOXYGEN preprocessor checks as they were inconsistent across the codebase.

Previously, the samplerate combo would display as a blank box in the
case that the device's actual samplerate wasn't one of the "available"
samplerates reported by the device.