Edit examples v0.50.0

- Updating examples/Makefile.am so it sends histyy.m with the simpleStatisticalInverseProblem, and so it sends simple_fp_plots.m with simpleStatisticalForwardProblem. 
- Editing makefile examples, eg Makefile_sfp_example_margarida, to reflect new QUESO version.
- Creating a new tex file for the examples, editing examples/validationCycle/src/exTgaValidationCycle_appl.h and examples/validationCycle/src/exTgaValidationCycle_gsl.C for looking correctly in the user's manual. Last edits in examples chapter before v0.50.0 release - unless we don't fix #185 and have to remove such examples from the user's manual.