* cygwinenv.sgml: Fix codepage:utf8 text in terms of setting
environment variables.
* new-features.sgml: New file describing new Cygwin 1.7 features.
Layout is preliminiary only.
* overview.sgml: Insert content of new-features.sgml.
* setup-net.sgml: Add "internet-setup" id anchor.
* overview.sgml: Update "What is it?" section. Add links to
"Is it free software?" section. Update "Brief History" section.
* overview2.sgml: Rewrite "Expectations for {Windows,Unix}"
as "Quick Start for those more experienced with {Windows,Unix}".
