Port Petaca to compile with gfortran

It compiles fine now with gfortran 4.9.2, patched with the patch https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60255#c6.

Unfortunately, there are some runtime failures, I suspect most of them are due to bugs in gfortran:
```
$ ctest 
Test project /local/certik/repos/petaca
    Start 1: fortran_dynamic_loader
1/9 Test #1: fortran_dynamic_loader ...........   Passed    0.00 sec
    Start 2: map_any
2/9 Test #2: map_any ..........................***Failed    0.00 sec
    Start 3: any_scalar
3/9 Test #3: any_scalar .......................***Exception: Other  0.00 sec
    Start 4: any_vector
4/9 Test #4: any_vector .......................***Failed    0.00 sec
    Start 5: any_matrix
5/9 Test #5: any_matrix .......................***Exception: Other  0.00 sec
    Start 6: parameter_list
6/9 Test #6: parameter_list ...................***Failed    0.00 sec
    Start 7: state_history
7/9 Test #7: state_history ....................   Passed    0.00 sec
    Start 8: secure_hash
8/9 Test #8: secure_hash ......................***Failed    0.40 sec
    Start 9: timer_tree
9/9 Test #9: timer_tree .......................***Failed    1.82 sec

22% tests passed, 7 tests failed out of 9

Total Test time (real) =   2.25 sec

The following tests FAILED:
	  2 - map_any (Failed)
	  3 - any_scalar (OTHER_FAULT)
	  4 - any_vector (Failed)
	  5 - any_matrix (OTHER_FAULT)
	  6 - parameter_list (Failed)
	  8 - secure_hash (Failed)
	  9 - timer_tree (Failed)
Errors while running CTest
```
So the next step after this PR is merged is to address those and report them as bugs to gfortran, or fix the Petaca code to work.