Ignore some mouse events sent from scrollbar to GUITable

Fixes #1567, #1806.
Add minetest.clear_registered_biomes() api
Schematics: Fix minetest.place_schematic() when defined by a Lua table
Mapgen V5: Fix use of uninitialized value in ctor
Fix regression (increase/decrease viewing range with +/- keys)
Restore finalColorBlend implementation in shaders.
Add space between client names in status text (client)

Before:
Server: version=0.4.10, uptime=190.5, max_lag=0.001, clients={user1,user2,user3,user4,user5,foobar,userplayedminetestthismorning}

After:
Server: version=0.4.10, uptime=190.5, max_lag=0.001, clients={user1, user2, user3, user4, user5, foobar, userplayedminetestthismorning}
Increase third person view distance

Signed-off-by: Craig Robbins <kde.psych@gmail.com>
Fix f6 debug/profiler display

After fonts were re-engineered the height of the f6 debug/profiler display would only display about 2-3 lines of text.