Element info keys : replace all -(minus) by _(underscore)

This change will brake all information with -(minus) from projects
created before this commit, but in the other side the use of data bases
for QET will be more easily to understand by avoid to replace the
-(minus) by _(underscore) in the tables of data bases.
Sorry for that, it's for your good.

elements/10_electric/20_manufacturers_articles/gce/disjoncteur.elmt

@@ -34,7 +34,7 @@ License: see http://qelectrotech.org/wiki/doc/elements_license</informations>
         <line y1="-4" y2="4" x1="16" x2="16" antialias="false" style="line-style:normal;line-weight:normal;filling:none;color:black" length1="1.5" length2="1.5" end1="none" end2="none"/>
         <line y1="90" y2="26" x1="10" x2="10" antialias="false" style="line-style:normal;line-weight:normal;filling:none;color:black" length1="1.5" length2="1.5" end1="none" end2="none"/>
         <input x="20" y="-30" size="9" text="_" rotate="true" tagg="label"/>
-        <input x="-13" y="-8" size="7" text="16A" rotate="true" tagg="tension-protocol"/>
+        <input x="-13" y="-8" size="7" text="16A" rotate="true" tagg="tension_protocol"/>
         <text x="-5" y="-71" size="6" text="IN"/>
         <text x="-9" y="87" size="6" text="OUT"/>
         <terminal x="-10" y="-90" orientation="n"/>