libgui|OpenGL: Detect NVIDIA CSAA support, use it if available

IssueID #1707
Script|libdeng2: Creating records with expressions

Previously it was only possible to create a new record using the
“record” statement or the Record() function. This commit makes it
possible to put “record” in front of any expression that refers to
an identifier, and that identifier will be created as a (sub)record.

For instance:

<pre># Old way:
record a
a.b = 1
record a.sub
# Alternatively: a.sub = Record()
a.sub.c = 2

# New way:
(record a).b = 1
a.(record sub).c = 2</pre>
Log|libdeng2|Client: Filtering log entries

LogBuffer can now use a separate filter object to decide whether
a log entry should be entered into the buffer or not.

Added LogFilter with fine-grained filtering parameters that allow
for per-domain minimum levels and developer messages. App stores
its log filter in the persistent Config as the record “log.filter”.

Added the -vv and -vvv options to more conveniently enable the
verbosity level. If these try to go beyond ‘extra verbose’, the
developer messages are enabled automatically. The -devlog and
-nodevlog options enable/disable the developer messages separately.

Also, the Config module was cleaned up by moving the constants
for Log and Updater into their own modules. This way the constants
are not saved persistently.
Fixed|Log|libdeng2: Checking the Dev flag in log entries
libdeng2|Script: Functions retain their original namespace

A function should use the global namespace where it was originally
created in.