h5hist: write overflow as boolean but still support string (#96)

* Write overflow as boolean but still support string

* Fix test

* Update version support

* Override h5hist v1.0

* RefValue unwrap

ext/FHistHDF5Ext.jl

@@ -28,8 +28,8 @@ function h5writehist(filename::AbstractString, path::AbstractString, h::Union{Hi
         for (dim, edges) in enumerate(h.hist.edges)
             write(g, "edges_$dim", collect(edges))
         end
-        attributes(g)["overflow"] = string(h.overflow)
-        attributes(g)["nentries"] = h.nentries.x
+        attributes(g)["overflow"] = h.overflow
+        attributes(g)["nentries"] = h.nentries[]
         attributes(g)["_producer"] = "FHist.jl"
         attributes(g)["_h5hist_version"] = string(CURRENT_H5HIST_VERSION)
     end
@@ -67,7 +67,7 @@ end
 function h5readhist(f::HDF5.File, path::AbstractString, H::Type{<: Union{Hist1D, Hist2D, Hist3D}})
     version = VersionNumber(read_attribute(f[path], "_h5hist_version"))
     version >= v"2" && error("h5hist $(version) is not supported")
-    version > v"1" && @warn """
+    version > sort(SUPPORTED_H5HIST_VERSIONS)[end] && @warn """
         h5hist $(version) is higher than the currently supperted one, some features might be missing.
         Supported versions: $(join(SUPPORTED_H5HIST_VERSIONS, ", "))
     """
@@ -79,7 +79,7 @@ function h5readhist(f::HDF5.File, path::AbstractString, H::Type{<: Union{Hist1D,
     hist = Histogram(edges, weights)
 
     sumw2 = _read_dset(f["$path/sumw2"], H)
-    overflow = parse(Bool, read_attribute(f[path], "overflow"))
+    overflow = read_attribute(f[path], "overflow")
     nentries = Base.RefValue{Int}(read_attribute(f[path], "nentries"))
     H(hist, sumw2, SpinLock(), overflow, nentries)
 end