[ctest] Add ctest continuous integration script for unix

Use with ctest [-V] -S.unix.ctest
[travis] remove old and obsolete travis file for osx [ci skip]
Merge pull request #90 from balint42/master

updated "contributing" doc
Merge pull request #98 from jgrewe/master

Getter of optional fields return boost::optionals
Closes #86 

Looks good to me!
Merge pull request #99 from balint42/master

removed "findEntities", completed use of "getEntities" & removed "children" methods
[ctest] Add ctest continuous integration script for unix

Use with ctest [-V] -S.unix.ctest
[travis] remove old and obsolete travis file for osx [ci skip]
Merge branch 'master' of https://github.com/jgrewe/pandora-1
DataArray: Add createData function and implement it for HDF5

Add this createData() function to:
- IDataArray
- DataArrayHDF5
- DataArray
DataArray: Add createData<T> for convenience
[test] DataArray::testData init the test array with 42.0 not 0.0

So we can actually check if the writing worked. Doh!
[test] DataArray::testData add checks for createData
Merge pull request #104 from gicmo/dataarray_createData

New methods on DataArray to explicitly create the underlaying data, i.e. the DataSet
DataArray: add getDataExtent method

IDataArray already had the method but it was not exposed in the
DataArray
[test] DataArray: test for correct DataSet extent
DataArray: move the setDataExtent to have *Extent() grouped

No logic changes, just cosmetic.
Merge pull request #105 from gicmo/getDataExtent

Add DataArray::getDataExtent and test it
Merge branch 'master' of https://github.com/G-Node/pandora
new tree_depth method in Section that gives the maximum levels below a
section
implemented Section::findDownstream(type) that is needed to find
related sections