deployFile allows for specifying a directory as destination, and copies
files into there, simulating the behavior of tools like cp. To do that,
it creates the directory, then appends the filename of the input file
to it and uses that as destination for the "copy file" call.
It's pretty handy for some applications to get the full path of the
new file returned by this method directly (doesn't have to implement
this concatenation more than once).
* Add symlinkFile to the public AppDir interface
* Rename AppDir::symlinkFile to AppDir::createSymlink
* change return value to bool
* Remove duplicated header
* Remove blank lines
* Add comment
* Fix test name
* Change createSymlink signature. Name changed to createRelativeSymlink and remove the useRelativePath argument
* Remove commented tests.
It's been a useful parameter, but only in some rare edge cases. Instead,
we'll focus more on desktop files, e.g., using the Icon entry contents
for (re)naming icons, etc.