Instead of relying on a hardcoded instance-name existing for the default-value, let's
look up the latest instance. This also resolves my problem where MacVim
had a servername of "VIM" instead of "GVIM".
Co-authored-by: Johann Fridriksson <jofridri@silabs.com>

This avoids spawning additional processes as $PWD **always** contains
the current working directory.

Added an <esc> to the begining of everything. I ran something when I was in insert mode once and all it did was shove !args... into the buffer.  <esc> first.

Added an optional callout to the end of the interaction function. I put it in to allow me to put the window focus on MacVim / GVim depending on the different OS I happen to be on

Fixed: If you callvim on a non-existant file with a relative path, the CWD of the running gvim process is used, and that's not right.  We use the PWD explicitly instead, in this case

Added an <esc> to the begining of everything. I ran something when I was in insert mode once and all it did was shove !args... into the buffer.  <esc> first.

Added an optional callout to the end of the interaction function. I put it in to allow me to put the window focus on MacVim / GVim depending on the different OS I happen to be on

Fixed: If you callvim on a non-existant file with a relative path, the CWD of the running gvim process is used, and that's not right.  We use the PWD explicitly instead, in this case