[vim] blockwise paste

[binora]

blockwise paste implementation

[binora]

@mightyguava @heppe Please have a look.

[mightyguava]

I found 2 bugs so far.

1. The block ends up getting pasted in the column before the cursor. It should be on the column after the cursor.
2. If the column the cursor on exceeds the length of the line below, vim should extend the line below with whitespace/tabs to match the column. Right now it just pastes to the end of the line.

[heppe]

@mightyguava I wasn't able to repro #1 from your list, but I don't see a commit after your comment, so I'm not sure how it might have been fixed.

I was able to see #2, however, and it's worse than you describe. It doesn't paste at the end of the line, but rather chucks out whatever contents were on the line past the shortest line that is touched by the pasted block. That definitely needs a fix and a test before this can be submitted.

[heppe]

LGTM. This looks ready to merge.

[mightyguava]

Merged as 9de315b