Add "copy_all_fields" option to transformPointCloud***() functions

So far different transform functions had inconsistend behavior. Some
copied the data in all fields, some did not. Following the discussion
in #575, this commit adds an option to control the copy behavior.
Add a helper class EventFrequency

A helper class to measure frequency of a certain event. To use this
class create an instance and call event() function every time the event
in question occurs. The estimated frequency can be retrieved with
getFrequency() function.
USC: fixed parameters / added descriptor-type

Fixed the descriptor parameters matching the values of the original
paper (Tombari et al. 2010). The former values have been copied from
3DSC-descriptor and have not been adapted.

Added a descriptor type UniqueShapeContext1960.

Modified test case to match the new UniqueShapeDescriptor.
Added sequence number and timestamp to clouds.
The squence number and timestamp provided by OpenNI2 are now added
to the point cloud header field of the clouds returned by the callbacks.
Transform point cloud in GICP align function
Set PCL_ONLY_CORE_POINT_TYPES on Windows (Closes #833)

We are hitting the 65k objects limit in Visual Studio in the feature
lib. Adding PCL_ONLY_CORE_POINT_TYPES means they need to include the
.hpp files if they use other point types and code may not be cross
platform compatible. On the other hand, all other compilers seem to be
fine.
Merge pull request #886 from nylocx/openni2grabberFrameIds

Added sequence number and timestamp to clouds.
Add a changelist for 1.7.2
Fixes #896.
Merge pull request #898 from mohawkjohn/emacs_style

Fixes #896.
Bump PCL version to 1.8.0
Moved pcl::PPFHashMapSearch::setInputFeatureCloud() and pcl::PPFHashMapSearch::nearestNeighborSearch() implementation from ppf_registration.hpp to ppf_registration.cpp since they belong to a not templated class
Merge pull request #900 from taketwo/bump-version

Bump PCL version to 1.8.0
Merge pull request #887 from VictorLamoine/gicp_fix

Transform point cloud in GICP align function
Merge pull request #850 from taketwo/add-event-frequency

Add a helper class EventFrequency
Merge pull request #805 from taketwo/fix-transform

Add "copy_all_fields" option to transformPointCloud***() functions
Merge pull request #891 from giacomodabisias/master

inlined setInputFeatureCloud() and nearestNeighborSearch()
Merge pull request #856 from jgarstka/USCfix

USC: fixed parameters / added descriptor-type
Merge pull request #897 from jspricke/windows_PCL_ONLY_CORE_POINT_TYPES

Set PCL_ONLY_CORE_POINT_TYPES on Windows (Closes #833)
Fix for issue #758