make a function to mark es-requests

remove/rename es-get-request-body to es-mark-request-body. I do this
because I want to mark the request under the cursor and use that further.

fix url-request-data after changing to mark
make es-at-current-header-p private, refactor

I don't think this is a function that should be used outside of the
mode.

string-match-p already returns `t` or `nil`.
factor out constant
beginning of line instead of check

if we are at the beginning of the line we know that there is not going
to be a header before on that line.
move to end of line before checking

if we move to end of line we are sure that we will not find the same
header as the one we are on.
when returns nil if it is not satisfied
do not use C-u as a prefix

C-u is already bound to `universal-argument` and should not be rebound.
refactor requests into 1 interactive function

Having multiple requests functions is confusing. This patch refactors
the different ways into 1 do-what-I-mean function. If you run it inside
a request body that does not have a header, the url and method is taken
from the vars. If the request body has a header, that header is used
instead. If you provide the function with a prefix `C-u` it will send a
request for each of the request-bodies in the buffer.
make es--perform-into-other-window private
Merge branch 'master' into ljos/sense-like-parameters
fix wrong function name
first element should be a var
Fix adding two URLs in some cases

We don't need to add the http prefix and we don't need to add the
default-base unless the beginning of the string is _.
we don't need add-http to be a function
fix error reporting, check for error in status
in-line private function that is only used 1 place
add new result-buffer for each query in the buffer
make es-find-params private
should not error on no fix, but return identity
fix marking query when at the end of body

When we are at the end of the body we should also "do the right thing"
and mark the body we are currently at.