support item templates for autocomplete and refactor ref-field

[harunurhan]

so this how it looks you can have a look (still WIP though), this is the cleanest way that I can think of, we can also use this this templates input for $ref fields in order to avoid dynamic definition and component loading.

UPDATE:

I also refactored the ref-field to use <template>, see second commit.

TODO:

• clean up example before the merging.

[coveralls]

Coverage increased (+0.08%) to 79.961% when pulling 460999f on harunurhan:templating-things into 77b3d80 on inveniosoftware-contrib:master.

[coveralls]

Coverage increased (+1.3%) to 81.199% when pulling 0c31b41 on harunurhan:templating-things into 77b3d80 on inveniosoftware-contrib:master.

[jmartinm]

Looks good to me.

[harunurhan]

@jmartinm I will update it and let you know when it's ready to merge

[zzacharo]

LGTM!

[harunurhan]

@jmartinm cleaned up config and example app, ready to merge.

[coveralls]

Coverage increased (+1.3%) to 81.18% when pulling 2578e59 on harunurhan:templating-things into 77b3d80 on inveniosoftware-contrib:master.