small fixes
steel column

--HG--
rename : structures/src/main/scala/org/encalmo/structures/common/section/IBeamSection.scala => structures/src/main/scala/org/encalmo/structures/eurocode/steel/IBeamSection.scala
rename : structures/src/main/scala/org/encalmo/structures/common/section/IBeamSection.scala => structures/src/main/scala/org/encalmo/structures/eurocode/steel/SteelColumn.scala
rename : structures/src/main/scala/org/encalmo/structures/common/section/Section.scala => structures/src/main/scala/org/encalmo/structures/eurocode/steel/SteelSection.scala
steel column test

--HG--
rename : structures/src/test/scala/org/encalmo/structures/AllStructuresWorksheetsUnitTest.scala => structures/src/test/scala/org/encalmo/structures/eurocode/steel/SteelColumnUnitTest.scala