vec<double> impl
vector<double> works
ResourceBuff improvements and better error handling.

* added overloaded PopQty with eps arg to ResourceBuff

* ResourceBuff re-zeros qty_ member if all resources have been popped - to
  better deal with floating point issues.

* better error messages for ResourceBuff exceptions

* try-catch around RunSim to avoid core dumps when exceptions are thrown
Merge branch 'rwcarlsen-buff' into develop
implements schema types for cycpp and trims strings for numeric types
Improved agent class doc comments a lot
fixed begincode->code doxygen errors
Merge pull request #945 from scopatz/vec

vector<double> for HDF5
Merge pull request #948 from scopatz/schematypes

implements schema types for cycpp and trims strings for numeric types
Merge pull request #949 from rwcarlsen/devdoc

improve agent class doc comments
added vector<float> to HDF5 backend
more reasonable greedy solver error message
updated default capacity to return the available node quantity. this was a bug that came to light thanks to radios work. previously, if there was a constraint, the minimum between the constraint and node total qty - node current qty was returned; however, if there were no constraints, MAX_DOUBLE was returned. now, in the absence of constraints, node total qty - node current qty is returned
fixed a bug in the greedy solver which treated request capacities as less-than constraints. e.g., if constraints were added for fuel with 5kg of u and 1kg pu, the constraint was satisfied as soon as either was true.
moved greedy solver related capacity querying to greedy solver files
a mass-based request constraint is now added automatically by the exchange translator, rather than requiring the user to call it manually.
Merge pull request #952 from scopatz/vec-float

added vector<float> to HDF5 backend
Merge branch 'e' of https://github.com/gidden/cyclus into gidden-e
Merge branch 'gidden-e' into develop
added overloaded functions