Updating to capnproto v0.8.0

- Includes some test stabilization
- Fixes manylinux2010 build issues (linker flag order due to old gcc)
- More rigorous python setup.py clean
- Requires capnproto v0.8.0 or greater
- Including system libcapnp include path for import (e.g. import
  stream_capnp)
- Bundle libcapnp .capnp files when not using system libcapnp
- Removing more distutils usage. Now using pkg-config to determine the
  system version of libcapnp (mainly for Linux, but should work on macOS
  with brew)
- Removed dead code

Resolves issues #215 #216 #217
Lots of fixes for Issue #218 (all sorts of retry methods needed for
GitHub Actions)

examples/async_calculator_client.py

@@ -55,6 +55,7 @@ async def main(host):
         print("Try IPv4")
         reader, writer = await asyncio.open_connection(
             addr, port,
+            family=socket.AF_INET
         )
     except Exception:
         print("Try IPv6")

examples/async_calculator_server.py

@@ -214,6 +214,7 @@ async def main():
         server = await asyncio.start_server(
             new_connection,
             addr, port,
+            family=socket.AF_INET
         )
     except Exception:
         print("Try IPv6")

examples/async_client.py

@@ -56,6 +56,7 @@ async def main(host):
         print("Try IPv4")
         reader, writer = await asyncio.open_connection(
             addr, port,
+            family=socket.AF_INET
         )
     except Exception:
         print("Try IPv6")

examples/async_reconnecting_ssl_client.py

@@ -86,6 +86,7 @@ async def main(host):
         reader, writer = await asyncio.open_connection(
             addr, port,
             ssl=ctx,
+            family=socket.AF_INET
         )
     except OSError:
         print("Try IPv6")

examples/async_server.py

@@ -116,6 +116,7 @@ async def main():
         server = await asyncio.start_server(
             new_connection,
             addr, port,
+            family=socket.AF_INET
         )
     except Exception:
         print("Try IPv6")

examples/async_ssl_client.py

@@ -65,6 +65,7 @@ async def main(host):
         reader, writer = await asyncio.open_connection(
             addr, port,
             ssl=ctx,
+            family=socket.AF_INET
         )
     except Exception:
         print("Try IPv6")

examples/async_ssl_server.py

@@ -128,6 +128,7 @@ async def main():
             new_connection,
             addr, port,
             ssl=ctx,
+            family=socket.AF_INET,
         )
     except Exception:
         print("Try IPv6")

examples/thread_client.py

@@ -30,7 +30,7 @@ class StatusSubscriber(thread_capnp.Example.StatusSubscriber.Server):
 
 
 def start_status_thread(host):
-    client = capnp.TwoPartyClient(host)
+    client = capnp.TwoPartyClient(host, nesting_limit=64)
     cap = client.bootstrap().cast_as(thread_capnp.Example)
 
     subscriber = StatusSubscriber()
@@ -39,7 +39,7 @@ def start_status_thread(host):
 
 
 def main(host):
-    client = capnp.TwoPartyClient(host)
+    client = capnp.TwoPartyClient(host, nesting_limit=64)
     cap = client.bootstrap().cast_as(thread_capnp.Example)
 
     status_thread = threading.Thread(target=start_status_thread, args=(host,))