Adding default mosquito multipliers.

Previously, the default behavior was for mosquito populations to be constant.
Now, the default is for them to vary proportional to average fraction of days
with precipitation reported in Merida from 1979 to 2013.  The default should
probably ultimately be set up differently.
Bugfix resulting from recent dynamic EIP changes

The _exposedMosquitoQueue was being initialized to the wrong size, potentially
resulting in segfaults.
Got rid of std:: in Parameters.cpp - NO OTHER CHANGES
Adding support for generating serotype patterns

Empirical serotype time series are "streaky", meaning serotypes tend to be
observed for several years in a row and then be absent for several years. These
runs and gaps appear to be approximately geometrically distributed.  We now
support randomly generating serotype introduction time series.  Currently the
geometric distributions are parameterized based on the serotype data we observe
for Yucatan.
Minor bugfix affecting output interpretation

We're printing daily "incidence" datat to stderr, but in the past it has
actually been daily infection counts, not daily NEW infection counts.  The
new output is labeled the same way, but now the values actually are what the
label claims.