Exporting dynamic rules file can result in 0xC2 chars in output

[jamesoff]

Steps to reproduce:

1. With advanced mode enabled, set some permanent rules and different some temporary rules, such that the permanent rules list on the left has at least one empty line
2. Click "Export to file"
3. Observe 0xC2 chars in the output where the blank lines were (appears as capital A with circumflex in browser window and %C2 in the data: URL)

uBlock 0.9.5.0 on Safari 8.0.6 on OS X 10.10.3.

(Edit: typo)