Increased version number to 1.3.1.
Backported fix from master.

Change input parameters used as return values to references; change
cached values due to the correction; disable slow test case.
Backport fix from master.

Disable non working test case.
Backport Markov functional model fixes from master.

- Remove cap for F (this causes violations of the C^1 property in
  certain cases). Require decreasing call prices for exponential
  extrapolation.
- Fix floor pricing.
- Fix error check in vanilla engine tests, exclude 0.10 strike and
  change strike 0.07 to 0.06 in cap engine test, use correct yield
  and volatility termstructure in cap engine test.
the expression mm*j can in general not be represented as int, therefore
we need to convert each factor to double before multiplying them
handle limit case strike (including displacement) equals zero
fix maturities for tn and sn quotes,
avoid generating too many quotes (and reading undefined array elements),
write 15 and 35 for the number of FRAs and Swaps entering the curve
throughout the code
avoid unsigned int overflow runtime errors. Although the code probably
works on most (or all?) existing platforms without the changes, strictly
spoken there are undefined subexpressions which we eliminate here.
fixed unsigned int conversion (thanks to Peter Caspers)
fixed index access
fixed index comparison int vs unsigned int
fixed clang warnings
replace int with Integer
fix warning during build
Merged pull request #31.

Some fixes for runtime errors occuring in the test suite
when running under clang's "-fsanitize=address,undefined,integer".
Backported fix from master.

the expression mm*j can in general not be represented as int, therefore
we need to convert each factor to double before multiplying them
Backported fix from master.

fix maturities for tn and sn quotes,
avoid generating too many quotes (and reading undefined array elements),
write 15 and 35 for the number of FRAs and Swaps entering the curve
throughout the code
Removed explicit typing from call to make_pair.

This prevents a compilation error on VC++ 2012.
Thanks to Ali Hassani for the fix.
Merge latest changes from R01030x-branch.
Merge pull request #32.