Fix permissions referring to "SSI" instead of "SSC"

Fixes #811
Merge /tphere into /tp, add /tppos
Improve /maxspawns and /spawnrate logic
Clean up pumpkin moon and frost moon commands
Add /time to allow getting the time and inputting 24-hour time
Fix help text
Add /forcehalloween, fix /hardmode to actually send changes, clamp tile positions in /tppos, remove extra permissions
Send WorldInfo when setting various time flags, fix time format
Merge pull request #814 from NyxStudios/commands

Another command overhaul
Add config option "RespawnBossSeconds"

Fixes #813
Merge branch 'general-devel' of https://github.com/NyxStudios/TShock into general-devel