Add destination filter options to client.conf

[michaelrsweet]

Add support for destination filtering options in client.conf, specifically:

# Browse local (mDNS) and registered domains (default)
BrowseDomains all

# Don't browse for printers via DNS-SD at all
BrowseDomains none

# Browse local (mDNS) domain only
BrowseDomains .local

# Browse named domains only
BrowseDomains .local,.example.com
BrowseDomains .foo.example.com,.bar.example.com

# Show all printers regardless of location
FilterLocation none

# Only show printers with matching location(s)
FilterLocation "Room 1"
FilterLocation "Room 1", "Room 2"
FilterLocation /^Room [1-2]$/

# Filter printers based on type(s)
FilterType any
FilterType mono
FilterType color
FilterType duplex
FilterType small
FilterType medium
FilterType large
FilterType duplex,color

These should automatically apply on top of the filtering offered by cupsEnumDests and friends. The filters apply to all destinations (even printers that are added locally) while the BrowseDomains setting only applies to DNS-SD lookups.

[michaelrsweet]

These changes should also be applied to CUPS 2.5.

[michaelrsweet]

Pushed these changes:

[master 2371ba8] Implement BrowseDomains, FilterLocation, and FilterType directives in client.conf (Issue #1180)

[master 44350b0] Fix a glitch with mono/color type filtering.

[master acfc975] Make location regular expression matching case-insensitive (Issue #1180)

Can also set the CUPS_BROWSE_DOMAINS, CUPS_FILTER_LOCATION, and CUPS_FILTER_TYPE environment variables to override the client.conf values. This is particularly useful with the "testdest" unit test program, e.g.:

cups/testdest --get | grep -e ':$'

CUPS_FILTER_TYPE="mono" cups/testdest --get | grep -e ':$'

CUPS_BROWSE_DOMAINS="none" cups/testdest --get | grep -e ':$'

CUPS_FILTER_LOCATION="/office/" cups/testdest --get | grep -e ':$'