readshapefile() raises incorrect error msg regarding shpproj and shapelib

まだ誰も着手していません。

When plotting a shapefile using readshapefile()

`m.readshapefile(shapefile_path, 'roads')`

I received this error message:

`ValueError: shapefile must have lat/lon vertices - it looks like this one has vertices
in map projection coordinates. You can convert the shapefile to geographic
coordinates using the shpproj utility from the shapelib tools
(http://shapelib.maptools.org/shapelib-tools.html)`

However, it appears that the specified module "shapelib" is no longer maintained or available. To add to the confusion, there is a completely different module that also goes by the name "shapelib" available on pypi and github, but that does not contain the functionality suggested above.

In regard to a suggested solution. I found the fix on this site to be useful for converting the shapefile and getting past this readshapefile() error.
http://fascicul.us/convert-display-shapefile-matplotlib.html

However, this conversion sometimes leads to a new error:

`ValueError: readshapefile can only handle 2D shape types`

Which I have yet to find a way to resolve

エントリーポイント readshapefile() から開始し、shapelib の shpproj を推奨するエラーパスを調査します。報告された変換と、その後の “only handle 2D shape types” という失敗を再現し、案内と処理のどちらが誤っているのかを判断します。エラーメッセージと変換の案内が、利用可能なツールとサポートされている shape タイプを正確に反映していれば完了です。

索引モデルが issue の本文から書いたものです。