Comment 7 for bug 779156

A postmortem:

+- command="`grep -E "^Exec(\[[^]=]*])?=" "$file" | cut -d= -f 2- | first_word`"
++ command="`grep -E "^Exec(\[[^]=]*])?=" "$file" | cut -d= -f 2- | sed -e 's/ .*$//'`"

This change was incorrect. "first_word" both "read"s one line and discards everything after a space. "sed" operates on many lines. Thus, more than on Exec in a desktop file are both legal and incorrectly joined together into command as "first\nsecond\third".