#6077: OpenGL2: Add r_ignoreDstAlpha.
Fix PNG tRNS length checks
Make GL2 MDR code use R_VboPackNormal for normal
Merge remote-tracking branch 'ioquake3/master'
Remove extra client_t::csUpdated[] slot

sv.configstrings[] is limited to 0 to MAX_CONFIGSTRINGS-1, make client_t::csUpdated[] the same.
Merge remote-tracking branch 'ioquake3/master'
Fix 'lightmap $lightmap' when there are no lightmaps

Using r_vertexLight or map with no lightmaps would dereference a NULL pointer.
Already fixed for 'map $lightmap'.