More build fixes. Changed the documentation builder to automatically prepend %EPOCROOT% (converted to a path relative form) to pre-processor include path options that start with 'epoc32'. Prevously $(EPOCROOT) was prepended in the makefile, which broke the documentation build because the pre-processor will only accecpt relative path include options.

---------------------------- Test U1 ------------------------------
1:X one
2:X two3:X three4:X four
5:X five
6:X six
7:X seven…8:X eight
9:X nine
10:X ten
---------------------------- Test U2 ------------------------------
12-Before 111
13-Before 222
14-Before 333…15:Match
16-After 111
17-After 222
18-After 333