Making tile scaling work with the Zoomify layer

Because zoomify tiles have different sizes, we also need to store the
standard tile size on the backbuffer. The Zoomify layer gets an override
for the createBackBuffer method to make sure that the native image size
is used.
Create capabilities format for WFS 2.0.0
WMTS createLayer method improved
OGC:CRS84 is a valid projection string too
Scale limits rounded to allow layer visibility at the end of the ranges
vars outside the loops
removed useless test on the existence of a style
Do not set serverResolutions and min/maxScale at the same time
always compute min/maxScales and set them in the layer config
updated tests
Do not allow dragging of unselected points in standalone mode
Fixing superclass constructor call
Merge pull request #1057 from ahocevar/zoomify-backbuffer

Making tile scaling work with the Zoomify layer
Add support for OGC filters 2.0
Mention uglifyjs compiler option in build options and README
Merge pull request #1072 from markhepburn/build-docs

Mention uglifyjs compiler option in build options and README
also trim the value of the priority field in SLD (follow-up to: #1048)
Merge pull request #1073 from bartvde/priority

also trim the value of the priority field in SLD (follow-up to: #1048) (r=@ahocevar)
Add ResourceId element
Add support for WFST 2.0 (transaction,getfeature)