Bundle built-in samples

[Gumichan01]

From LMMS/lmms#1257 (comment)

built-in samples should be bundled because the future of LMMS is not guaranteed to contain the same exact built-in samples.

Difficulties:

• Built-in samples are in LMMS/data/samples/
• Some user samples are in LMMS_data/samples/

The path to LMMS samples is not known, so the user has to provide it manually.
I can reduce the burden by just letting the user provide the path to the LMMS directory (/path/to/lmms/) so I can get /path/to/lmms/data/samples and calculate /path/to/lmms_data/samples This soluton is platform dependent. The user has to provide information about where built-in samples are, because he/she must know where he/she installed the program.

This is not the best solution but it could do the job.

[Gumichan01]

Including built-in samples must be done by providing the path to the samples directories in LMMS and LMMS data locations.

--lmms-dir "path/to/LMMS_Data/samples/" "path/to/LMMS/data/samples/"

You can specify multiples paths.

Commit 946800b fix this issue.