doc: remove reference to config.mk, hangulin.txt

needed to get `make html` to work.
doc: remove generated manpages
doc: remove some unnecessary targets

these files got all imported, no ned to create them
doc: remove encoding conversion targets

this deletes the source files wich have an utf-8 generated file.
in the next step the generated *UTF-8.1* files will be renamed.
doc: rename `*.UTF-8.1` files
doc: remove uganda.nsis.txt target

It seems that this file was used in the windows installer as license
file.
doc: move manpages into their own folder
doc: remove links that point nowhere

`make html` displays errors for links that are not in the tagfile
doc: update gitignore
doc: use `cat` instead of `more` to display errors

`more` may cause the travis build to hang
doc: add new doc files to Makefile
doc: fix links to index.html and vimindex.html
Merge pull request #1011 from stefan991/cleanup-docs

Cleanup user documentation build