Naming consistency; saving window config; lighter

[kaushalmodi]

Hi,

The following implementation to make the interleave mode work with pdf files viewed using pdf-view did not work for me; it started throwing error backtraces.

(defun interleave-pdf-view-after-page ()
    "Go to the page's notes after the page has been changend with `pdf-tools'."
    (interleave-go-to-page-note (pdf-view-current-page)))

  (add-hook 'pdf-view-change-page-hook 'interleave-pdf-view-after-page)

So I went ahead and reverted my fork to the earlier implementation of simply redefining the interleave-- functions if pdf-view is used.

In addition, I made few house-keeping and minor feature-addition changes:

• All the package variable and function names now begin with interleave--
• Added explicit definition of the doc-view-kill-proc-and-buffer function (from emacs 24.4 source) in the package itself as that function's behavior changes to a mere current buffer kill in emacs 25.1 onwards.
• The window configurations are saved and restored when entering and exiting the interleave mode.
• interleave-create-new-note function is modified to enter a new line if the point is not already on a new line.
• interleave--create-new-note and interleave--add-note functions are modified to use the new interleave--switch-to-other-window function.
• interleave-docview-mode is renamed to a more generic name interleave-pdf-mode because the pdf file could be viewed in doc-view-mode, pdf-view-mode (pdf-tools) and any other mode too?
• interleave mode lighter changed to ≡ for its succinctness

[rudolfochrist]

WOW! Thanks for your effort.

[kaushalmodi]

Thanks for accepting the pull request! :)