Enhance getPage in PageFactory

New PR to develop instead of master see #89.

Closes #12 
I don't get what this does. In line above we've added `\` at the end of namespace. Here we're checking there there is no `\` at the start of namescape (which after doing `trim` above only can happen if namespace is empty) and we add `\` in front of it.

Maybe we should more explicitly define what we normalize (just guessing what you normalize):

1. no trailing `\`
2. always have `\` in front