Fix join lines so that only a single space will exist between two lines that are joined.
Scan buffer to remove trailing whitespace
Add spec for joining from empty line
Add trailing whitespace to line
:lipstick:
Removed added newline
:memo: form -> from
:memo: Correct typos
Always move to end of current line
Merge pull request #3860 from atom/ks-join-line-single-space

Join lines with a single space