fix retrospective scrolling on opening
add a marker line, that keeps track of the equivalent of a 'last read' state of the console
let ctrl-pos first jump to the markerline and on second use to the top of the console
and don't scroll over the top
add additional scrollfunctions for use in mousewheel+ctrl and potentially others
Port client logging from Tremfusion.
add con_scrollLock for configuring behavior of when to scroll down to the last line again

 * 0: no scroll lock at all, scroll down on any message ariving
 * 1: lock scrolling if in scrollback, but scroll down for send message/entered commands
 * 2: lock scrolling if in scrollback, even for own output
 * 3: always lock scrolling
fix markerline marking already removed lines after /clear has been invoked

thanks to DevHC for pointing out this issue
remove the cl_IRC_kick_rejoin feature
Prevent crashes when r_deferredShading > 0
Fix 4f7d857a7170a2580ce0a0c69bed7a72d73267c0. Shotgun works as expected now.

In the bad commit, Q_crandom() allowed negative values into the sqrt. This led to bad things happening (like not all the shotgun shots would hit where expected.)
Add comments that describe the range of Q_random and Q_crandom

Fuma wants them. The functions themselves aren't exactly descriptive at a glance.
Set cl_renderer GL if GL3 crashes during shader compilation.

In a release build, GLSL shader compiliation usually means that the hardware does
not support GLSL shaders and should rely on vanilla instead.
Fall back to vanilla renderer if OpenGL version < 2.1

OpenGL 2.1 introduced GLSL version 1.20 which introduced a few features that we use
We also specify #version 120 in the shader text
Print a few short interesting bits of OpenGL information by default to help with debugging user issues
Remove a few useless or duplicate things from q_shared.h
give out the current used entity count in /entitylist to get actual entityamount instead of the poolsize
Make PrintInfoLog work for both glsl shader objects and program objects
Remove old, unused, and wrong glsl optimizer code
Add missing glsl preprocessor definitions

This fixes some depreciation warnings in the shader compile log for glsl versions 1.30 and up