improve

* print signal number
* print full path name for addr2line
* print base and symbol addresses for addr2line
fix and update offset
change end to _end
update readme
Update README.md
improve
Merge branch 'devel' of github.com:justmao945/StackTrace into devel
add sigbus
fix format
fix re to match + 0
add threads test
clean code
xxx
Merge pull request #1 from justmao945/devel

Devel