The command used for linking to the core library was "@library{core}"
instead of correct "@library{wxcore}". This resulted into plain text
"page_libs_core" being displayed instead of expected "wxCore" hyperlink.
Closes https://github.com/wxWidgets/wxWidgets/pull/1259
No real changes, just clean up sources by removing trailing spaces from
all the non-generated files.
This should hopefully avoid future commits mixing significant changes
with insignificant whitespace ones.
