Completed opcode table.

Added tests along with opcode table entries for:
ORA, PHA, PHP, PHX, PHY,PLA, PLP, PLX, PLY, ROL, ROR, RTI, RTS, SBC,
SEC, SED, SEI, STA, STX, STY, STZ, TAX, TAY, TRB, TSB, TSX, and TXA