custome elements don't work with java 8

What steps will reproduce the problem?
1. install java 8 as system default
2. open umlet
3. open the custom element creator

What is the expected output? What do you see instead?
Expected: default custom element successfully displayed
Instead: displays "custom element with errors"

What version of the product are you using? On what operating system?
occurs on both 12.0 and 12.2, Mac OS x 10.8.5

Please provide any additional information below.

had attempted my umlet (12.0) dependent project on a windows 7 machine with the 
same results but assumed that it was windows being windows now it occurs to me 
that it is java 8 related, today I upgraded to eclipse luna (from indigo) to 
recover support for other dependent projects that now need java 8. if i run 
everything with java 6 the other projects throw some errors while umlet works 
fine

Original issue reported on code.google.com by TJAur...@gmail.com on 10 Jul 2014 at 8:25

Merged into: #183

achuanle / umlet

custome elements don't work with java 8 #187