update klayout to 0.27.4

0.27.4 contains bug fixes on DRC and LVS.

Changelog:

• Enhancements: Some enhancements on the 2.5d view (e.g. live layer color update, z only scaling, wire frames, etc.)
• Enhancement: simple versions of DRC with_holes/without_holes without parameters
• Enhancement: LVS netlist compare performance improvements in certain cases
• Enhancement: #914 Make "tap" function available in reader mode
• Bugfix: Decent error message (not crashing) when trying to create a cell or layer on an empty panel
• Bugfix: DRC crash
• Bugfix: Crash when deleting a hierarchical PCell library from Python
• Bugfix: Spice reader ignores last line
• Bugfix: Fill Tool crashes
• Bugfix: border case GDS file behavior restored
• Bugfix: Font path can be selected for standalone "Basic" library
• Bugfix: Python module does not build from sources
• Bugfix: Typo in separation_check signature
• Bugfix: Clarification of device parameter compare on LVS

A complete list of changes can be found at https://www.klayout.de/development.html

As before, open a few GDS files (kB to GB in size) and browse the layout. Open Help->About and check it ruby/python bindings are present in the `Build options'.

 
- Open a few GDS files (kB to GB in size) and browse the layout.
- Open Help->About and check it ruby/python bindings are present in the `Build options` and ~20 .so files are present in `Binary Extensions`.
- Start python3, import `klayout` and `pya` modules.