Improvements and bug fixes made

Hi all, I've added some bug fixes and optimizations to Pas6502.  If a conditional statement only has one logic part, like "if a = 3 then" it will produce a new fragment with "_l1" at the end of the file name.  The "_l1" part represents the false label to jump to in the fragment code.

The compiler will expect a branch to a true part and a jmp to the false label {l1} in the fragment, and won't require leaving $ff or $00 in the accumulator as a true/false result anymore.

For example the fragment example below would change from:

lda {m1} + 1
cmp #>{c1}
bcc !isTrue+ // msb <
lda {m1} + 0
cmp #{c1}
beq !isTrue+
bcc !isTrue+
lda #$00
jmp !+
!isTrue:
lda #$ff
!:

to
lda {m1} + 1
cmp #>{c1}
bcc !isTrue+ // msb <
lda {m1} + 0
cmp #{c1}
beq !isTrue+
bcc !isTrue+
jmp {l1}
!isTrue: