Fixes VS14 build. SqlCEHelper.cs - the compiler in Vs14 doesn't like that we're callng `public IRecordsReader ExecuteReader(string commandText, params IParameter[] parameters)` like this: `ExecuteNonQuery("alter table [" + table + "] drop constraint [" + constraint + "]");`

Added two internal method overloads that just send an empty parameter array instead.
Moves fix for VS14 to the SqlCEHelper class itself, InternalsVisibleTo didn't seem to work in VS (worked on command line build though)
Merge pull request #516 from nul800sebastiaan/vs2014

Fixes VS14 build.