Refactor error/warning handling
subprocesstest: mock warning rather than hoping it's right
Rename tests to put test- at front
IO: hide abortOnError better

It's only for IO::err, so restrict its use to a private constructor.
doxygen updates
Rudimentary IO class tests
Wait status formatting knows about stopped processes.
Test for Date::monthLength
Rudimentary test for Directory class
New --dump-config option.
Markdownify README
Fix typography in disk encryption notes
perl hasn't been a dependency for ages
Remove the old perl version
Improvements to manual