Fixes/changes:
some bugfixes esp. in the setevar() and initialize() functions
Fixed (completely rewrote) processing of varname in commandline (now it
works as it should have).

New features:
1) New command AL (ALias) by request of Stuart Axon:
al alone will display the aliases that are set.
al alias will clear the alias "alias" if it is set
al alias real command.

DOG will check for the first word on the command line, if it is an alias, if
it is it will replace the alias with the "real command". DOG will do
recursive aliases up to 20 levels of recursion. This is to avoid unlimited
recusrion if you have set Foo=BAR and BAR=FOO you could potentially end up
in an infinite loop if you say foo or bar.

-A will set the size of the alias block (default is 256 bytes)

Remade the DOG int D0 functions. Here are the new specs:

Int D0
******

DOG - Get version
AH = 01h

Return:
AX = Version
	 
Notes:
Version is built up like this:

A H  A L
---  ---
| |	 | |
| |	 | +-- code maturity allways one of a (=alpha), b (=beta) OR f (=final)
| |  +---- Patchlevel
| +------- Minor version
+--------- Major version

(this implies that the maximum version for DOG is 15.15.15f ;)
------

DOG - Get internal variables:
Call with: AH = 02h
           AL = what variable
AL=01 Returns DX = environment segment ;ES:BX points to envseg variable
AL=02 Returns DX = alias segment ; ES:BX points to aliasseg variable
AL=03 Returns CX = number of strings; ES:BX points to commands
AL=04 Returns CX = number of strings; ES:BX points to ext_commands
AL=05 Returns CX = number of strings; ES:BX points to commands_des
AL=06 Returns CX = number of strings; ES:BX pointsto ext_commands_des
AL=07 Returns ES:BX points to bf (first bf param block)