Add more detailed help

[hoglet67]

This may cause us to overflow 16KB again

Do this in a way that can be disabled in the godil_250 builds, using a flag in the Makefile.

[obiwanjacobi]

Make (github.io) internet pages that have the extended text. Report small error texts with a short link to these help pages?

[hoglet67]

Managed to fit this in quite easily:

>> help
ICE-65C02 In-Circuit Emulator version 0.96
Compiled at 19:18:40 on Nov 13 2019
8 watches/breakpoints implemented
Commands:
    blist     
    breakr    <address> [ <mask> [ <trigger> ] ]
    breakw    <address> [ <mask> [ <trigger> ] ]
    breakx    <address> [ <mask> [ <trigger> ] ]
    clear     <address>
    compare   <start> <end> <to>
    continue  [ <reset> ]
    copy      <start> <end> <to>
    crc       <start> <end>
    dis       [ <start> [ <end> ] ]
    fill      <start> <end> <data>
    flush     
    help      [ <command> ]
    history   
    load      <address>
    mem       [ <address> ]
    next      
    rd        [ <address> [ <count> ] ]
    regs      
    reset     
    save      <start> <end>
    special   [ <value> ]
    srec      
    step      [ <instructions> ]
    test      <start> <end> [ <test num> ]
    trace     [ <instructions> ]
    trigger   [ <address> <trigger> ]
    watchr    <address> [ <mask> [ <trigger> ] ]
    watchw    <address> [ <mask> [ <trigger> ] ]
    watchx    <address> [ <mask> [ <trigger> ] ]
    wr        <address> <data> [ <count> ]
>> help load
    load      <address>
>> help save
    save      <start> <end>
>>