release EasyBuild v2.3.0

bump version to 2.3.0 and update release notes

mention list of software names for which custom sanity check paths needed to be added in easyconfigs

{cae}[*/2015b] OpenFOAM 2.3.1 + deps

{lang}[intel/2015b] R 3.2.1 (REVIEW)

{lang}[foss/2015b] R 3.2.1 (REVIEW)

{tools}[GCC/4.9.2] p7zip 9.38.1 (REVIEW)

add ABySS-1.3.7-intel-2015a-Python-2.7.9.eb

Add SOAPdenovo2-r240-intel-2015a.eb

add --exclude unpack options for OpenFOAM 2.3.1 to dancy around cyclic symlink causing problems when unpacking

{devel,bio}[*/2015b] BLAST+ 2.2.31 + Boost 1.58.0 (REVIEW)

{chem}[*/2015b] CP2K 2.6.1 + deps (REVIEW)

{tools}[GCC/4.9.2] parallel 20150822 (REVIEW)

add --exclude unpack options for OpenFOAM 2.3.1 to dancy around cyclic symlink causing problems when unpacking

{lib}[*/2015a] NFFT 3.3.0 (REVIEW)