Added document lines that name the default device drivers.

Also:
- Changed some <htmlurl> tags to <url>.  Now, those links will show their URL addresses (in addition to their names) in info and text pages.
- Added some Atmos-specific function names to its document.
- Fixed some punctuation syntax.

doc/atari.sgml

@@ -7,7 +7,7 @@
 url="mailto:shawnjefferson@24fightingchickens.com"
 name="shawnjefferson@24fightingchickens.com"> and
 Christian Groessler, <htmlurl url="mailto:chris@groessler.org" name="chris@groessler.org">
-<date>03-Jan-2006
+<date>2014-03-27
 
 <abstract>
 An overview over the Atari runtime system as it is implemented for the cc65 C
@@ -412,7 +412,7 @@ The values of "1" are needed because the graphics command crashes if
 it doesn't have at least one byte available. This seems to be a bug of
 the Atari ROM code.
 
-Default drivers: <tt/atr8.tgi (atr8_tgi) and /<tt/atrx8.tgi (atrx8_tgi)/.
+Default drivers: <tt/atr8.tgi (atr8_tgi)/ and <tt/atrx8.tgi (atrx8_tgi)/.
 
 <sect1>Extended memory drivers<p>
 
@@ -657,7 +657,7 @@ Command line arguments can be passed to <tt/main()/ when DOS supports it.
 <item>Leading and trailing spaces around an argument are ignored.
 <item>The first argument passed to <tt/main/ is the program name.
 <item>A maximum number of 16 arguments (including the program name) are
-      supported.                                                       
+      supported.
 </enum>
 
 
@@ -700,7 +700,7 @@ segments should go above &dollar;7FFF.
 <p>
 The main problem is that the EXE header generated by the cc65 runtime
 lib is wrong. It defines a single load chunk with the sizes/addresses
-of the STARTUP, LOWCODE, INIT, CODE, RODATA, and DATA segments, in 
+of the STARTUP, LOWCODE, INIT, CODE, RODATA, and DATA segments, in
 fact, the whole user program (we're disregarding the "system check"
 load chunk here).
 <p>