SPI-2368: upgrade eigen 3.3.0 --> 3.4.0
Update Eigen to 3.4.0 and update ltwnn to the very latest one
To run the testing, add a comment with:
Bot test PACKAGE[ PACKAGE2 ...]|all in TOOLCHAIN|all [(only|also) for LABEL-COMPILER-BUILDTYPE] please!
To ensure patches required for existing LCG branches are not lost, please add the respective labels: alsoTargeting:LCG_102-patches, alsoTargeting:master, etc.
Edited by Dmitri Konstantinov