updated docs to mention it

update meson.build to try to fix for MacOSX

add new help_all function to the API, and cleaned the previous help API function so it works with the old batchmode

cleaned up the stellar magnitudes code a bit (to annoy Gio mostly ;)

fix issue with return type of strerror_r being dependent on GNU or XSI compliance: now we just ignore it (we only really want the errstring anyway)

available we don't try to use them

default to mersenne twister for random numbers when ieee754 and hence drand48 are not available e.g. on Mac

updates to fix format statements when using mersenne twister

fix difflog casting issue on mac

update meson.build to check for objcopy

add error case in binary_c-config when shared library cannot be found

sync latest perl mods

* fix FILE_OFFSET_BITS check
* fix FPU check

update docs to say what internal_buffering does

update CHANGES for 2.1.6 release

update docs and code to remove old references to ./configure

update install script to fail more obviously