Rename "libADLMIDI" project

[Wohlstand]

The "libADLMIDI" is not a part of original ADLMIDI and it's too different internally to identify "ADLMIDI" and "libADLMIDI" as same project. This will confuse people are will find original project by "ADLMIDI" key where is no any library.

First in my idea is to rename project into "libOPLMIDI" like I made "libOPNMIDI" from the name of the chip. But it's would be another better variant?

Originally, libADLMIDI has founded as a fork of ADLMIDI as the work to turn it into the library. Later, the library was reworked deeply, refactored and equipped with new parts are replaced older or extending existing.

[mmontag]

I like "libOPLMIDI", seems very descriptive and accurate.