Fix issues related to undefined names for set_chorus_speed and set_ch…

[nwhitehead]

…orus_depth.

Turn docstring for load_libfluidsynth into raw string to avoid warnings about illegal backslash escapes.

Fix broken fallback branch of sfpreset_name method.

Clamp pitch bend values and fix max value in docstring.

Fix tuning_dump function to have a python api.

Update example SoundFont instrument to turn on reverb in single preset.

Add new test showing off reverb.

Bump api_version constant because api is affected by this commit.

Rename "set" to "flag", poorly chosen local variable name.