Introduced support for adding SHA1 hash valued location markers
at several levels in the language specification, added long explanatory
comment at the end, added a script 'addlatexhash.dart' to normalize
spacing, remove comments, etc., in the spec, such that the hash values
are more robust than they would be with a direct usage of the spec.
The script passes the "dvi2tty test", that is, when the location markers
are empty, the resulting *.dvi files created from dartLangSpec.tex and
from the version processed by the script give rise to the same text via
dvi2tty, i.e., the script does not destroy the spec.
R=gbracha@google.com, ricow@google.com
Review URL: https://codereview.chromium.org//646003002
git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@41191 260f80e4-7a28-3924-810f-c04153c831b5
eernst@google.com
bf339367c3