Fix a memory leak in `freeClass()` exposed by valgrind's memcheck

In `msGrowClassLabels()` memory is assigned to
`class->labels[class->numlabels]` but was only freed to
`class->numstyles-1` in `freeClass()`.  This fix ensures the last
label is freed.
Revert "Fix a memory leak in `freeClass()` exposed by ... memcheck"

This reverts commit 4b90c2404f4b3209f491ab84780f735fba4a119d which as
discussed in issue #4685 is not a valid solution.
Ensure class labels are free'd in cases where label loading fails
Install postgresql-9.1-postgis-2.0-scripts in Travis due to packaging change of postgis
updated msautotest to latest branch-6-2 revision
solved symbol size trunc bug thanks to tbonfort
Merge pull request #4699 from luipir/branch-6-2

fix integer rounding on sld se:size (#4699)
printed color alpha value in map file
Add proxy and auth support to wfs client (#3982)

Copied & adapted from similar code in mapwmslayer.c.

Fix two copy-pasto errors while here, wfs_http_cookie was not
looked up.
Move the common code handling proxy/auth metadata statements in a single function
Add support for shapefiles with uppercase extension on Linux (#4712)
test for msHTTPAuthProxySetup() return value against MS_SUCCESS
Merge pull request #4707 from luipir/branch-6-2

print color alpha value in map file writer
Merge pull request #4685 from homme/grow-class-labels-leak-fix

Fix a memory leak on failed parsing in `freeClass()` (#4685)
avoid rendering symbols with 0 scale (#4654)

sending in symbols with a 0 zero scale seems to mess up cairo, even
though our use of cairo_save/cairo_restore should have taken care
of this.
Merge branch 'branch-6-2'

Conflicts:
	.travis.yml
	mapfile.c
	msautotest
Merge branch 'master' of github.com:mapserver/mapserver
add major changes in HISTORY.TXT for 6.4
Merge pull request #4708 from landryb/master

Add proxy and auth support to wfs client (#3982)
Add support for coveralls code-coverage reporting in travis builds