Use "expl3-generic" as loader name for format-independent use

Also tidy up a bit of the naming written to the log: name is always
'expl3', use 'loader' and 'code' to show which part is which.


git-svn-id: http://www.latex-project.org/svnroot/experimental/trunk@4725 de43f980-851b-0410-b2f7-c40aca1f87e0
Announce "L3 Module: ..." in log

Minor, largely cosmetic, change.


git-svn-id: http://www.latex-project.org/svnroot/experimental/trunk@4726 de43f980-851b-0410-b2f7-c40aca1f87e0