make the preset command use ord() and delta patterns

now you can do things like @pre k0,>=5 t537,+1 which will ensure skill id 0 is greater than or equal to 5, and will give 1 item id 537

simple patterns:

• 5
  • absolute value of 5 (implicit)
• =5
  • absolute value of 5 (explicit)
• >5
  • initial value, greater than 5
• <5
  • initial value, less than 5
• >=5
  • initial value, greater than or equal to 5
• <=5
  • initial value, less than or equal to 5
• +5
  • initial value, plus 5
• -5
  • initial value, minus 5
• ++
  • maximum value
• --
  • minimum value

combined patterns:

• +5|<9
  • initial value, plus 5, but less than 9
• ++|-5
  • maximum value, minus 5