Fix testsuite in octave (tested in 4.8.2 under Windows) by properly escaping `\t` (like in MATLAB) by `\\t`
fix #401 mandrillaImage being reversed

Reversing the image if axis is invisible is not needed.
Manual test with R2011b and R2014b by commenting out `axis off` in test case.
Removed black background to allow visual control, if axis is really of.
Merge pull request #420 from PeterPablo/fix_#401_ACID_mandrillaImage

fix #401 mandrillaImage being reversed
Merge pull request #419 from PeterPablo/fix_#415_ACID_octave_new

Fix #415 acid octave
trailing whitespace
New ACID test: image orientation

Systematic test of image orientation (`XDir` and `YDir`) and axis visibility (`axis off`)
Split test to cover inline code and external PNG

* imageOrientation_inline works as expected
* imageOrientation_PNG fails due to bug, unrelated to test
Fix inlining images in TikZ code
Fix inlining images in TikZ code
Merge pull request #423 from PeterPablo/fix_ACID_114_image_inline_v2

[ACID]Fix testcase 114 imageOrientation_inline
Merge pull request #422 from PeterPablo/ACID_new_test_imageOrientation

[ACID]New tests image orientation
Remove duplicate test imageplat

It was replaced an extended by `imageOrientation_PNG`
and `imageOrientation_inline`.
Merge pull request #424 from PeterPablo/remove_duplicate_test_imageplot

Remove duplicate test imageplot