Page "Formats": a list of extensions in the input field is now synchronized with the general list.
PPageMisc: center-align buttons
CPPageExternalFilters: fix a warning

The warning was introduced in d5e3c09
Also assign values to struct members in the order the struct was defined
CPPageFormats: fix warnings introduced in 9c67509
Merged pull request #77.

Conflicts:
	src/mpc-hc/mpcresources/mplayerc.de.rc