Note: This assumes there are no spaces at the end of lines.
Example Text:
Praesent commodo cursus magna, vel scelerisque nisl
consectetur et. Nulla vitae elit libero, a pharetra
augue. Curabitur blandit tempus porttitor. Maecenas
faucibus mollis interdum. Donec ullamcorper nulla
non metus auctor fringilla. Cras mattis consectetur
purus sit amet fermentum.
Find:
([A-Za-z0-9_.,!"'/$()])\n([A-Za-z0-9_.,!"'/$()])
Replace:
$1 $2