Make the build system aware of the 1.7 JDK (which icedtea reports itself as) and add an explicit check and complaint if we find a JDK that we don't support.
Make the build system aware of the 1.7 JDK (which icedtea reports
itself as) and add an explicit check and complaint if we find a JDK
that we don't support.

jamesthomp/pgjdbc,davecramer/pgjdbc,lonnyj/pgjdbc,zapov/pgjdbc,Gordiychuk/pgjdbc,panchenko/pgjdbc,AlexElin/pgjdbc,bocap/pgjdbc,jorsol/pgjdbc,zemian/pgjdbc,underyx/pgjdbc,tivv/pgjdbc,davecramer/pgjdbc,AlexElin/pgjdbc,rjmac/pgjdbc,jkutner/pgjdbc,golovnin/pgjdbc,tivv/pgjdbc,jamesthomp/pgjdbc,amozhenin/pgjdbc,bocap/pgjdbc,lonnyj/pgjdbc,jkutner/pgjdbc,jkutner/pgjdbc,alexismeneses/pgjdbc,lordnelson/pgjdbc,whitingjr/pgjdbc,panchenko/pgjdbc,underyx/pgjdbc,phillipross/pgjdbc,whitingjr/pgjdbc,thkoch2001/libpostgresql-jdbc-java,Gordiychuk/pgjdbc,jorsol/pgjdbc,sehrope/pgjdbc,marschall/pgjdbc,rjmac/pgjdbc,pgjdbc/pgjdbc,jamesthomp/pgjdbc,ekoontz/pgjdbc,marschall/pgjdbc,zemian/pgjdbc,whitingjr/pgjdbc,lordnelson/pgjdbc,marschall/pgjdbc,schlosna/pgjdbc,pgjdbc/pgjdbc,pgjdbc/pgjdbc,panchenko/pgjdbc,AlexElin/pgjdbc,amozhenin/pgjdbc,pgjdbc/pgjdbc,jorsol/pgjdbc,alexismeneses/pgjdbc,amozhenin/pgjdbc,ekoontz/pgjdbc,sehrope/pgjdbc,zapov/pgjdbc,rjmac/pgjdbc,thkoch2001/libpostgresql-jdbc-java,lordnelson/pgjdbc,zemian/pgjdbc,phillipross/pgjdbc,schlosna/pgjdbc,marschall/pgjdbc,sehrope/pgjdbc,zapov/pgjdbc,davecramer/pgjdbc,golovnin/pgjdbc,bocap/pgjdbc,jorsol/pgjdbc,phillipross/pgjdbc,underyx/pgjdbc,golovnin/pgjdbc,sehrope/pgjdbc,davecramer/pgjdbc,thkoch2001/libpostgresql-jdbc-java,Gordiychuk/pgjdbc