Use a fixed body in response header tests

This lets us stop munging the expected length betwen HEAD and GET, and
lets us test Content-Length when using an external sever too.
Back to 0/1 for true/flase setting for autoflush

From IRC:
<ilmari> I'd rather use 0 than undef for false, really
<vanstyn> ok, then I'll change it back... the reason I changed it to
undef was to match existing code, 'abort'
<vanstyn> I generally prefer 0/1 as well, which is why that is what I
started with
API change: autoflush (log) now on by default + unit tests + POD

The new autoflush feature of Catalyst::Log now defaults to true and is
left on. In order to access the old behavior, modules such as
Static::Simple must manually turn it off (i.e. by hooking
setup_finalize, see example in POD).

Also updated logger unit tests, and added a new set of
autoflush-specific tests.

Note: this API change was suggested by mst
Misc tweaks per mst

Log still flushed at the end of setup + Catalyst::Log::_log() returns 1
version 5.90065

Fixed file modes...
Merge branch 'master' of https://github.com/laufeyjarson/catalyst-runtime