Extra spaces cause lyric pasting to repeat words

Steps to reproduce bug
1. Copy the following text:

   I copied a word.  
   I copied it twice

2. Open a score with lots of notes in it (such as promenade demo)
3. Select a note and choose Create > Text > Lyrics
4. Ctrl+V multiple times until all the words have been pasted as lyrics

Expected behavior: Extra spaces, tabs, and line breaks are often used for poetry. When pasting into MuseScore the extra whitespace should be ignored. The result should look something like:
I copied a word. I copied it twice

Actual behavior: MuseScore pastes nothing when there are multiple spaces in a row. Syllables after multiple spaces are pasted multiple times. The result actually looks something like:
  I I copied a word.  I I copied it twice

MuseScore version: r. 3679 nightly trunk

(Operating System: Windows 7)