make pages to be default if a type other then post is defined. This
avoids having problems in feed and archive with dates. Allows us to
define another templates for each page type.
we don't need to iterate here.
1. asciidoc operates in unsafe mode by default now. No problem for us
because WE are generating our sites. 
2. asciidoc set base dir to be jbake root, now it is easy to
include::content/* in our asciidoc sites.
correction to post <-> page swap as default
fix test cases. Rendering is locale dependent so error was Februar
insted of February.
asciidoctor.options has now multiple values per key.
before the latest overwrote the previous. The default.property
asciidoctor.options=source-highlighter=prettify if still overwritten
when custom property is defined.
asciidoc options are now supported via keyprefix asciidoc.option.KKK
where KKK is the asciidoc key.
some asciidoc options are typed. Passing a string is not an option.
Because we don't know the type we guess them by their content. not
perfect but ok for boolean,int and string.
Merged in #54.
Reverted change in convention re: posts & pages for time being. Also set
Asciidoctor to UNSAFE mode in code.