Fix invalid unref
Define I6 compiler name in terms of version

Since the I6 version is now a configure variable, also define the
executable name in config.h.
Refactor index page names into I7Panel

This array should be constant and also public for I7Panel.
Update git.mk and use its new features

Updating git.mk to latest allows us to take out some files that had
previously been in DISTCLEANFILES and MAINTAINERCLEANFILES.
Enable tests during 'make check'

However, skip all the tests that create an I7App object -- they
require reading data files and starting the compiler, and so will fail
during make distcheck because the data files are not installed.
Update to latest Chimara

Fixes Mantis #1135 and #1187.

http://inform7.com/mantis/view.php?id=1135
http://inform7.com/mantis/view.php?id=1187
Set default spellchecking language to English

It doesn't make sense to spellcheck in a non-English language yet,
until Inform gains the ability to program in other languages. This
picks your most preferred English variant if your system has one; if
not, it defaults to my preferred variant.

Fixes Mantis #1209.
http://inform7.com/mantis/view.php?id=1209
Count whitespace lines as blank when indexing

When indexing the headings for the Contents panel, although section
headings should be preceded and followed by a blank line, lines
containing whitespace should be counted as blank. The Inform compiler
allows this and so does the syntax highlighting.

Fixes Mantis #1206.
http://inform7.com/mantis/view.php?id=1206