add topaz font
do not delete savestate on load
implement scrollit and load_tick_element
fix price calculation due to bogus gethundreth()
dont sleep too long in main loop

leads to long processing times at the start of the game and
unresponsiveness to user input.
use real rand() instead of timer-based randomness

i suspected the bad rng may be the cause of the price problems.
however this turned out not to be the case.
implement SetDrMd

this partially fixes the graphic glitches in the graphs page.
the * characters were drawn with the background color (black)
instead of leaving the green background untouched (JAM1 mode).
the glitch with the black X displayed in the blue bar still persists.
handle margin command
activate jump command

the command is used to jump over weeks,
using it as JUMP 0 is currently the only way to continue after
"END OF QUARTER".
in the original hitting F10 seems to have the same effect,
but translation of function keys is not yet done in this version.
change build system so location of ezsdl.h can be customized
import ezsdl.h

ezsdl.h is a header with all inline functions for easy usage
of sdl (C) me, myself and I.
implement DisplayBeep
activate BONDS and CASH commands

BONDS is called T-BILLS in the original, but internally BONDS is
used everywhere, so i renamed it.
the bought BONDS are displayed in the lower righ corner in the
"T-" display, and can be sold with CASH.
fix error message when stock is missing from command
implement display_rankings()
fix offset at which 'bottom' starts

the exact value may need further tuning but this one is sufficient
for own use.
fixup for HEAD^2
add put command processing
improve kbhit()

- recognize events that need screen refresh (like fullscreen toggling)
- recognize F1-F10 keys (needed to access some info screens)
  (F10 or the JUMP 0 command are required to continue the game at the
   end of a quarter).
- drop processing of other special keys (ALT would be interpreted as "4")
implement change_player()

function is called via F1-F4 and serves 2 purposes:
1) switch cur_player to player 1-4
2) toggle the 2 pages of informations for that player
   page 1 displays stocks, page 2 "auto" options, such as put options.