gene expressions: AND now has higher precedence than OR

commit 2a7a5dfdf6628ab7c949703cd394d9506ef6fcdf is also reverted
test
Eflux2 takes new CSV file to set bounds
MOST now parses iaf1260_nobound txt gene expressions
bugfixes
Eflux2 takes mean of gene expression values
Eflux2 works properly (no bounds are incorrect)
E-Flux2 cleaned up, load only the iaf126 model and gene_expr.csv
Removed test comment