Comment 6 for bug 414594

Here's my patch as discussed in IRC. It basically creates a launcher script which gracefully handles XDG_DATA_DIRS and the case of installation into a relative prefix.

If the system has readlink installed, relative prefix installation is supported; otherwise, the generate-launcher script will fail with an error message. The readlink utility is not required for absolute path installations (the vast majority of cases).

Before committing, chmod +x tools/generate-launcher