Fix PHP building when GD is disabled. Closes #4550
Merge branch 'branch-6-2' of github.com:mapserver/mapserver into branch-6-2
ignore additional encodings in received content-type headers (#4585)

closes #4585
fix cgi label commands after multi-label changes (#4621)
Don't entity-encode URLs used on attributes: libxml2 does this for us. Refs #4622
update msautotests for #4622
use ows_schemas_location for sld_capabilities ref (#4624)
update autotest submodule for #4625 and #4624
add a script to run full test suite (build + test run)
Parse key value pairs sent in POST body (#4627)

Backported from the master branch.

Conflicts:
	msautotest
fixups to build/test scripts
Fix for WMS requests with width and height of 1 (#4629)
OGR WFS output: do not force null integer values to 0 (#4633)
update submodule for backported fix of #4633
updated submodule for #4633
Ensure that `msCopyLabel` copies `expression` and `text` directives
Fixed problems found in the mapfile.xsd while trying to convert current mapfiles into xmlmapfiles
Exposed labelObj.text and labelObj.expression in PHP/MapScript (closes #4310)
Move #4577 fixes out of libmapserver
Updated mapserver.h and HISTORY.TXT for 6-2-1 release.