The EL impl library in external/el-impl.jar is patched with file from the 'patches' directory.

Steps for creation of the patched el-impl.jar:
1, checkout the EL project from http://java.net/projects/el-spec/sources
2, apply the patch over the sources - the patch must correspond with the downloaded version:
{PATH_TO_THE_REPOSITORY}/el-spec~source-code$ patch -p0 < {COMPLETE_HG_REPO}/libs.elimpl/patches/el3_0_4.diff
3, build the Expression Language project
4, from the JAR remove the public API - classes of the 'javax.' package
