some missing export, added stable doc badge

Author: nantonel

README.md

@@ -4,6 +4,7 @@
 [![Build status](https://ci.appveyor.com/api/projects/status/06wd5jckd8fhdi1v/branch/master?svg=true)](https://ci.appveyor.com/project/nantonel/structuredoptimization-jl/branch/master)
 [![codecov](https://codecov.io/gh/kul-forbes/StructuredOptimization.jl/branch/master/graph/badge.svg)](https://codecov.io/gh/kul-forbes/StructuredOptimization.jl)
 
+[![](https://img.shields.io/badge/docs-stable-blue.svg)](https://kul-forbes.github.io/StructuredOptimization.jl/stable)
 [![](https://img.shields.io/badge/docs-latest-blue.svg)](https://kul-forbes.github.io/StructuredOptimization.jl/latest)
 
 StructuredOptimization.jl is a high-level modeling language

src/syntax/expressions/abstractOperator_bind.jl

@@ -68,12 +68,14 @@ end
 for f in  importedFFTW[:,1]
 	@eval begin
 		import FFTW: $f
+        export $f
 	end
 end
 #importing functions from DSP
 for f in  importedDSP[:,1]
 	@eval begin
 		import DSP: $f
+		export $f
 	end
 end
 #exporting functions

src/syntax/terms/proximalOperators_bind.jl

@@ -1,6 +1,7 @@
 # Norms
 
 import LinearAlgebra: norm
+export norm
 
 """
 `norm(x::AbstractExpression, p=2, [q,] [dim=1])`
@@ -208,6 +209,7 @@ sumpositive(ex::AbstractExpression) =
 Term(SumPositive(), ex)
 
 import LinearAlgebra: dot
+export dot
 
 """
 `dot(c::AbstractVector, x::AbstractExpression)`
@@ -291,6 +293,7 @@ end
 # Rank constraints
 
 import LinearAlgebra: rank
+export rank
 
 # Dirty trick: the "rank" function only makes sense in constraints such as
 #   rank(X) <= r,