Merge branch 'libedit-deps-fix' into 'master'

Libedit deps fix

Configuration fix
-----------------

Situation:
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Currently there are three problems when configuring the sources:

1. When configuring with `--with-libedit=/is/somewhere/else` the header files location is not passed into appropriate translation units and the compilation fails on missing header file `histedit.h`.

2. Compilation fails with `--disable-daemon` and `--enable-utilities` because libedit is pulled by static dependencies of utilities but is not detected in the configuration because of disabled daemon.

3. Sources of  `knotc` are compiled with daemon but the resulting binary is only built(linked) when utilities are also enabled, because utilisties provide necessary static `libknotus.la`.

Solution:
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* Add missing `$(libedit_CFLAGS)` into `src/Makefile.am` on relevant places.
* Presence of libedit is checked when configuring with daemon **or** utilities.
* Changes in `src/Makefile.am` so that `libknotus.la` is built when `HAVE_DAEMON` or `HAVE_UTILS`. Utility `knotc` is compiled and built with `knotd`.

See merge request !529