Fix handling when parsing ASCII with minus sign
ZRTP can now use Curve3617 if it uses bnlib library
Merge branch 'newcurve' into develop
Add Curve25519 Diffie-Hellman key agreement
Change License from GPL to LGPL

In general files that hold my Copright are now using LGPL. Other sources in
this project may have their own licenses. Please refer to the source files.
Prepare a V4.0.0 release
Merge branch 'newcurve' into develop