Save the last used "open file" and "recording" directories

[Wikinaut]

Compiled your program from github without problems. Thanks for it.

I wish that the last used directories are saved. I mean, after having selected a file-to-speak in ~/user/projects/this-and-that/file.txt it would be nice that a second file open automatically opens ~/user/projects/this-and-that/ directory.

Similar for recordings: the last directory should be stored.

Advantage: avoid heavy user navigation in the file tree.