v0.20.2

• Fix combining nef error.

v0.20.1

• Update toolchain example to MobileNet v2.
• Fix knerex bias adjustment.
• Fix knerex shared weight with same name support.
• Fix other bugs.

v0.20.0

• Support text procssing models.
• Set flatbuffer as the default 720 compiling mode.
• Refactor compiler and analyser inner structure.
• Due to the structure change, batch compiler do not backwark support previous bie files.
• Refactor toolchain manual.
• Bug fixes.