Cherry-pick "Merge branch 'FixLCG91SystemLibs-1.0-20180123' into '1.0'" into master
Various Fixes For LCG_91 System Externals, 1.0 branch (2018.01.24.)
See merge request !215 (merged)
(cherry picked from commit 884e13df)
- 32466662 Wrote a package that would build libxml2 as part of the analysis
- 38724f6e Taught the ROOT build how to make use of the libxml2 library built by
- 1c4b6015 Forcefully disabled ROOT looking for BLAS. Since on lxplus-like machines
- 9df3b2c4 Made the ROOT build mandatory in projects that build libxml2.