two new pull requests

[Alex Liberzon]

Thanks to Roi and his students few bugs were discovered and (hopefully) fixed in these pull requests. Both relate to the Matlab packages: 

1. openpiv-matlab 

the pull request is linked, please review it. all users are strongly recommended to update their software: https://github.com/OpenPIV/openpiv-matlab/pull/3 

the images are now read by a unified function openpiv_imread that treats TIFF images (12-bit from Insight) or any other format accordingly. 

the directory listing is also fixed, there was a bug with the upper-case extensions on Mac OS X platform

2. openpiv-spatial-time-toolbox

there were two bugs:

a) the y-axis direction was upside-down, compatible with the C++ version, but not with the openpiv-matlab, openpiv-python or Insight

b) the profiles were upside-down when used by columns. 

the pull request that shall improve the situation is here: https://github.com/OpenPIV/openpiv-spatial-analysis-toolbox/pull/11

Please, note that in order to get this one, we have to merge or to close  first the previous one: https://github.com/OpenPIV/openpiv-spatial-analysis-toolbox/pull/10 

[Alex Liberzon]

if no reviews will happen till the end of the next week, we'll merge it based on our own test.