Abstracted format and more strict method signatures
introduced FileFormat
[BC] changed Format interface
[BC] changed Detect constructor signature, old style is kept in Detect::initByPath() factory method
[BC] Learn accepts Format instead of path to output
examples update
tests update
include autoloader dev dependency
 add gitignore for composer vendor
update readme.md to include latest signature changes
Merge pull request #7 from mente/abstract-format

[BC] Abstract format