Get rid of 'ambiguous definition' warnings in base/floatfuncs.jl

Base library functions 'round', 'ceil', 'floor' and 'trunc' now can have second Integer argument (defined in base/floatfuncs.jl). This caused warnings about ambiguous definitions during loading of package Sims.

One warning still exists during loading Sims in recent Julia version. Are there any ideas how to resolve it?
```
julia> using Sims
Warning: New definition
    BranchHeatPort(Union(Unknown{UAngle},Number,RefUnknown{UAngle},MExpr,Abstrac
tArray{T,N}),Union(Unknown{UAngle},Number,RefUnknown{UAngle},MExpr,AbstractArray
{T,N}),Union(Unknown{UHeatPort},Number,RefUnknown{UHeatPort},MExpr,AbstractArray
{T,N}),Function,Any...) at D:\Documents and Settings\PGR\.julia\Sims\src\rotatio
nal.jl:57
is ambiguous with
    BranchHeatPort(Union(Unknown{UVoltage},Number,RefUnknown{UVoltage},MExpr,Abs
tractArray{T,N}),Union(Unknown{UVoltage},Number,RefUnknown{UVoltage},MExpr,Abstr
actArray{T,N}),Union(Unknown{UHeatPort},Number,RefUnknown{UHeatPort},MExpr,Abstr
actArray{T,N}),Function,Any...) at D:\Documents and Settings\PGR\.julia\Sims\src
\electrical.jl:26.
Make sure
    BranchHeatPort(Union(Number,MExpr,AbstractArray{T,N}),Union(Number,MExpr,Abs
tractArray{T,N}),Union(Unknown{UHeatPort},Number,RefUnknown{UHeatPort},MExpr,Abs
tractArray{T,N}),Function,Any...)
is defined first.

julia>
```