This either changes the pkgbase to match the directory name
or the other way around.
The motivation for this is to make it possible to automatically generate
an URL to the PKGBUILD file from the package information alone.
1. add -DECM_MKSPECS_INSTALL_DIR= to MSYS2_ARG_CONV_EXCL so mkspecs files are placed in /mingw{32,64} instead of /msys{32,64}/mingw{32,64}
2. change deprecated LIB_INSTALL_DIR with KDE_INSTALL_LIBDIR
3. place mkspecs files in ${QT5_PREFIX}/share/qt5/mkspecs (Qt5 mkspecs dir) instead of ${QT5_PREFIX} which points to root /mingw{32,64}
* upgrade some broken packages
* correct some broken urls/checksums
* use secure urls where possible
* update PKGBUILD templates
* remove line-ending whitespace
* minor typos/fixes
Remaining md5sums either didn't download or
didn't pass checksum tests.
The plugin gets built as a dll, since qt5-static/cmake doesn't
have support for building static plugins, though I could try
changing SHARED to PLUGIN to see if that fixes it.
