This reverts commit f3ffe0b325.
Sending a control sequence to the host terminal, wrapped in DCS, causes
problems because it changes the state of the host terminal outside the
screen's control. This change will therefore be reverted.
Note: there are three changes to ascii_isident. Reverting first two (in
find_special_key and first in get_special_key_code) normally fails the new test
with empty &isident, but reverting the third does not. Hence adding `>` to
&isident.
Ref vim/vim#2389.
Regarding the individual items in the header:
`Vim - Vi improved by Bram Moolenar`
Bram Moolenar is already mentioned throughout the documentation, as
well as the intro screen.
`:help uganda`
It's already shown to all users who don't use `shortmess+=I` upon
starting nvim, and is already placed prominently in help.txt, i.e.,
`:help` run with no arguments.
`:help credits`
Already mentioned near the top of help.txt.
`README.md`
Already mentioned in develop.txt.
Move files from src/ to src/nvim/.
- src/nvim/ becomes the new root dir for nvim executable sources.
- src/libnvim/ is planned to become root dir of the neovim library.
