Changed file to compile with my opencmissextras
User defined line search method - Brent's with golden section

Tracker item: 3696
User defined linesearch method

Brent's with golden section search

Tracker item: 3696
Debug FE and contact matrices
Merge branch 'linesearch' into linearisation

Conflicts:
	src/problem_routines.f90
FE + contact debug
Brent goldensection linesearch

Tracker item: 3497