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(cherry picked from commit f4c32733)

(cherry picked from commit d789b155)

(cherry picked from commit 24d3ed8f)

(cherry picked from commit aca87df3)

It helps with reproducible builds, by not including the source path
in the public header files.

Related to evolution#1273

This change helps to create reproducible builds. Even the glib-mkenums
is not called in the sources, it'll be better to sync the GLibTools.cmake
content with the evolution-data-server, in case anybody uses this project
as a template for another module and will use the glib-mkenums.

Related to evolution-data-server#281

(cherry picked from commit 7a298ea3)

closes #3

(cherry picked from commit ce317f57)