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
runtime: fix executable bit on some files
build: install with the correct permissions

The install() command will create the parent directories, but it does so
with the user's umask.  We want to do our best to make sure the correct
permissions are being set, without clobbering existing permissions.

To do this, this commit introduces an install_helper(), which is similar
in signature to the install() command, to help ensure that directories
are created ahead of the actual install() command.  This will attempt to
use 0644 permissions for files and 0755 permissions for directories by
default--though they can be overridden.

To make this work correctly, without trying to introduce some mechanism
with setting the umask, it meant that there's a small portion that makes
use of an "internal" version of the file() command.  It has been tested
on CMake 2.8.11, 2.8.12, and 3.0.2, and works correctly on all versions.

This fixes #1201 and #1086.