Fixed out-of-GOPATH parsing

Lots of nice things before v2:

• Add support for local go module outside of GOPATH. It only works well if "remote" and "local" paths match.
• Fix panicweb on macOS.
• Wrap errors where applicable on go 1.13 and later.
• Ran staticcheck and fixed all warnings.
• Fixed tests on 32 bits when -race is not supported.
• Many internal refactoring in preparation for v2.

Lower IsPtr floor to 4MiB; slightly faster

Most of the changes are test-only changes to help in preparation for v2.

The only user visible changes are IsPtr floor was lowered from 8MiB to 4MiB and processing is now a bit faster and more memory efficient.

New package webstack

The new package webstack enables in-process panicparse!

Go 1.13 support, indented output

• Add support for stack trace generated by Go 1.13beta1.
• cmd/panic includes more ways to panic, including very deep stacks.
• Add support for indented output.
• (Currently disabled) Add support for race condition parsing. Need more refactoring to enable.

Minor internal refactoring

Improve parsing internal logic, in preparation for race detection.

Make panic work on go1.7.6, will be needed to find

go.mod; fix unit tests

• Updated dependencies and switch from gopkg to go mod.
• Palette was moved from stack to internal; it was never meant to be exposed publicly.
  • Please ping the maintainer if this breaks you.
• Fixed unit test to work on go1.11 and later.
• Stopped using github.com/maruel/ut.

More refactoring in package stack is planned but this will be tagged as v2 since this will change the signature.

vendor/ trim and update

No functional change.

• Removed github.com/maruel/ut as a testing dependency, which trimmed the vendored tree.
• Updated other dependencies.

Features release

This is a feature release. It includes changes in the last 3 months:

• Guess $GOROOT and $GOPATH from the stack trace, and try to match with local value.
• New -html flag, currently rudimentary until someone who knows CSS contributes improvements. wink wink
• Add cmd/panic, to generate various style of stack traces.
• Silence SIGQUIT only when reading from stdin.

Fix crash when parsing non-matching source files

Maintenance release.

Fixes

Improvements by @gwik and @kshvmdn; better parsing of map, chan and CRLF.