Improve relative>absolute filename option handling

Relative -> absolute filename handling now occurs for the following flags:
 -I
 -F
 -iquote
 -include

Rather than just -I.

Backslashes are now no longer erroneously removed, and can be used as an
escape character on posix systems.

Relative->absolute filename handling should be more robust in general.
fixed bash path in Makefile

Signed-off-by: Oliver Pinter <oliver.pntr@gmail.com>
Make all include path absolute, so that it is no longer needed to change the working directory
Add global functions for GotoDeclaration().
Add GotoDeclaration functions to documentation.
Merge pull request #402 from kevincox/master

Made GotoDeclaration functions public.
Merge pull request #390 from Andrew-Dunn/better_absolute_paths

Improve relative>absolute filename option handling
Merge pull request #400 from opntr/master

fixed bash path in Makefile
Merge pull request #403 from Arnaud-de-Grandmaison/issue372

Make all include path absolute, so that it is no longer needed to change...
Makefile fix: SHELL should be set to /usr/bin/env bash not $(/usr/bin/env bash)
Merge pull request #404 from crucerucalin/master

Makefile fix: SHELL should be set to /usr/bin/env bash not $(/usr/bin/en...
Fixed jumpToLocation path containing spaces - added backslash to escape the spaces
Merge pull request #405 from branoh/fix-jumpToLocation

Fixed jumpToLocation path containing spaces
Merge pull request #399 from modk/master

Simple hack to allow tab in insert mode when completing function arguments
Revert "Simple hack/fix to allow tab in insert mode when completing function and template arguments"

This reverts commit d9dccefca96f95a1d1543425dec33fbfadd7daf0.

This caused conflicts with supertab and ultisnips. I revert it for now.

I still like this functionality, but we obviously need to design it
better.
Merge pull request #409 from tobig/revert-tab-in-insert-mode

Revert "Simple hack/fix to allow tab in insert mode when completing func...
set mark when jumping to location in current file

The normal mode command m' was there before but got broken by commit 6f491682: m without the single quote is not a normal mode command. When changing files, the jump list is already updated.
Merge pull request #410 from brunodefraine/patch-1

set mark when jumping to location in current file
Merge