Adding a polynomial nonresonant model

[lhenry]

Babar Bd -> KsKK non-resonant model described in arXiv:1201.5897 uses a polynomial NR component described as a sum of a S-wave term and a P-wave term, each being a second-degree polynomial in x = m12 - omega (omega being a physical offset). One has to : Implement a new LauAbsResonance class evaluating as S-wave or P-wave depending on its name, and as a polynomial term of degree 0 to 2 depending on its name.

[lhenry]

(In [65]) Creation of the LauPolNR class and corresponding changes in LauAbsResonance and LauResonanceMaker. Adding of a ignoreMomenta flag in LauAbsResonance as well. oktotest #19

[Thomas Latham]

(In [72]) Some improvements to LauPolNR and a couple of small changes to LauBelleNR. addresses #19

[Thomas Latham]

(In [73]) Backout changes to GenFit3pi example that were accidentally committed in previous commit. re #19

[Thomas Latham]

(In [76]) Some additional functionality for the CoeffSet classes:

• allow the parameter values to be set (optionally setting the initial and generated values as well)
• allow the parameters to be set to float or to be fixed in the fit

These are needed when cloning but wanting some of the parameters to have different values and/or floating behaviour from the cloned set. Improve the printout of the setting of the coefficient values in the fit models and the creation of resonances Fix bug setting resAmpInt to 0 for LauPolNR Add LauFlatNR for the unform NR model - ends its rather strange special treatment Many other improvements to the info/warning/error printouts Modify GenFitBelleCPKpipi example to demonstrate cloning in action Add -Werror to compiler flags (treats warnings as errors) addresses #19 addresses #20