eclib v20160101

No non-trivial changes to code, and none to the library interface. Various obsolete compiler flags have been removed, and documentation updated (see github issue #10). A new configure option --disable-mpfp has been added but the beaviour with the default is unchanged. The shared library revision has been incremented so the library is now named libec.so.2.0.3 instead of libec.so.2.0.2