update version to 0.11.8, and add dist-es6 to gitignore (tensorflow#1109

)

* update version to 0.11.8, and add dist-es6 to gitignore

* remove dist-es6 from gitignore

Update to 0.11.7. (tensorflow#1097)

Bump version: 0.11.5 --> 0.11.6 (tensorflow#1088)

WebGL Backend: Centralize async reading of data, postpone disposal if…

… a pending read (tensorflow#859)

BUG
FEATURE
PERF

All the work involves only the WebGL backend.

- Centralize async reading of data in a single setTimeout loop
- Postpone disposal if there is a pending read
- Use LRU cache to page textures out of the GPU memory and into CPU (Avoids crashing browser)
- Some optimizations:
  - Cache the `ext.GPU_DISJOINT_EXT` parameter since reading it is expensive
  - Do binary search for queryIsDone since checking is expensive
  - Reuse download buffers for readPixels to minimize js memory trashing

Did a stress test using demos/mnist_eager where I made tensor.dispose() a no-op. There is significant slowdown (~10x) due to constant downloads and js GC trashing memory, but the browser doesn't crash. The optimizations I did were motivated by the profiling from this stress test.

Fixes tensorflow/tfjs#394

Update version to 0.11.4 (tensorflow#1072)

Bump core version: 0.11.2 --> 0.11.3 (tensorflow#1071)

increase version to 0.11.2 (tensorflow#1057)

Bump version to 0.11.1 (tensorflow#1056)

* Bump version to 0.11.1

Update version to 0.11.0. (tensorflow#1047)

Bump version to 0.10.1 (tensorflow#1035)

* Bump version to 0.10.1