Add ctags make target (#1110)
Add ctags make target (#1110)

Exclude sub/web/ad_manager/static/js/ as ctags otherwise prints warnings
like:

ctags: Warning: ignoring null tag in sub/web/ad_manager/static/js/d3.min.js
klausman/scion,FR4NK-W/osourced-scion,klausman/scion,FR4NK-W/osourced-scion,Oncilla/scion,klausman/scion,klausman/scion,Oncilla/scion,netsec-ethz/scion,netsec-ethz/scion,dmpiergiacomo/scion,klausman/scion,FR4NK-W/osourced-scion,FR4NK-W/osourced-scion,dmpiergiacomo/scion,dmpiergiacomo/scion,Oncilla/scion,netsec-ethz/scion,netsec-ethz/scion,Oncilla/scion,dmpiergiacomo/scion,dmpiergiacomo/scion,dmpiergiacomo/scion,FR4NK-W/osourced-scion