npm module: imread with relative file path

[dangerdak]

Passing a relative path to imread results in the error:

/.../test-propel/node_modules/propel/propel.js:10560
        throw error;
        ^

Error: ENOENT: no such file or directory, open '/Users/rld/src/propel/sample.png'
    at Object.fs.openSync (fs.js:667:18)
    at fs.readFileSync (fs.js:572:33)
    at fetch2 (/.../node_modules/propel/propel.js:10689:20)
    at Object.fetchBuffer (/.../node_modules/propel/propel.js:10745:18)
    at nodeImageDecoder (/.../node_modules/propel/propel.js:27853:31)
    at Object.imread (/.../node_modules/propel/propel.js:27875:22)
    at run (/.../test-propel/run-model.js:36:22)
    at <anonymous>

shell returned 1

Possibly because the npm module still has the line: var __dirname = "/Users/rld/src/propel/src"; (in v3.3.1)?

[qti3e]

To resolve #375, Ryan implemented a new function at 9116ff2 (fetchWithCache) and we need to use this new function in im.ts instead of directly calling fetch function (util.ts).