Updated all rct tunnel wall models to have less verticies

Updated guide rail models
Added dg2 guide rail models

Fixed lighting on rnd_a / rnd_b models

Added gmod_berlin_dsp_manual model

Fixed lighting error in junction models

Updated g1a sign models
Updated Sign texture and material
Updated rnd_a / rnd_b models

Updated swt_slip_single_l_p2_c / swt_slip_single_r_p2_c models

Adjusted length of css_br_*_p2_a.mdl & css_br_*_p2_c.mdl

Added missing tunnel cable ends
Adjusted diagonal 3rd rail endings
Fixed diagonal cross switch 3rd rail
Adjusted tunnel platform stair railings
Fixed diagonal powerfeeds
Fixed diagonal straight 3rd rail
Fixed roof_rct_b pieces length
renamed rf_rct_rmp_rs_bnksgh_r_b.mdl to rf_rct_rmp_rs_bnk_sgh_r_b.mdl
Fixed misaligned bank2 supports, round roof
Fixed platform branch / diagonal platform ends
Fixed misaligned 3rd rail on switches
Updated guide rail endings
Added missing guide rail endings
Minor update to signal materials
Minor update to signal models
Fixed tunnel detail models
Added dsp models
Updated dg_b_l_256_sgh_rnd* models
Updated both clock models
Updated signal models for RenderTarget
Updated dsp tile models for RenderTarget

Fixed rct_rnd pieces
Split rct_rnd pieces into a, b and c parts
Added missing collision to rct_rnd pieces
Fixed *pt_ed_rail2.mdl
Updated Signal Models
Updated spt_mtl models
Updated all cable models
Updated all 3rd rail models

Warning! Origin of rct_rnd_b pieces changed!