writeMap(): Adding ANGLE to directives saved

ANGLE is missing in the directives for the generated mapfile, when
calling mapfile.c:writeMap() ; this commit aims to save the custom
angle.
Merge pull request #5006 from pmauduit/angle-when-writeMap

writeMap(): Add ANGLE to saved directives (#5006)
OGR style: support more options for Pen and Brush (#4982, #4983)

- For pen, support 'p' (pattern), 'cap', 'j' (join) and 'dp' (perpendicular offset)
- For brush, support 'a' (angle), 's' (size), 'dx'='dy' (gap)
msOGRUpdateStyle(): split it in 4 subfunctions. No functional change
OGR style: handle multiple combined tool and support 'l' (priority level) (#4982, #4983)
update msautotest
add missing entries to label copies
For debugging: add env. variable MS_HTTP_HEADER that can be set to NO in the non-MOD_WMS_ENABLED mode to avoid emitting HTTP headers
Improve previous commit when msIO_setHeader() is called before any call to msIO_Initialize()
Remove MS_HTTP_HEADER hack to use mapserv -nh existing mechanism
Add -h/--help option to mapserv binary to display help message
Extend default message displayed when launching mapserv without argument, to advertize --help
Add comment to mention that MS_ENABLE_CGI_CL_DEBUG_ARGS is diabled because of security concerns
Add missing dll export
Fix crash when copying a map with label leaders
Merge pull request #5013 from mapsherpa/patch-1

Fix crash when copying a map with label leaders
Remove atexit() call on Win32 code path that cause crashes on mapserv

Reported on http://lists.osgeo.org/pipermail/mapserver-dev/2014-October/014269.html
The cleanup done by the atexit() callback is redundant with the one done
by msCleanup(0) at the end of the main().
Fix crash on CONNECTIONTYPE kerneldensity on Windows (#5019)
Fix wrong use of iconv() that caused encoded_text pointer to be moved and corrupted (#5025)
msLayoutTextSymbol(): fix memory corruption in case of failed iconv() (#5025)