Bump glog to 0.7.0

[aleksraiden]

Update google log to 0.7.0. Full release notes here: https://github.com/google/glog/releases/tag/v0.7.0

Key features

• C++14 is now the primary language standard
• google::EnableLogCleaner(unsigned) has been superseded by google::EnableLogCleaner(std::chrono::minutes)
• google::LogSeverity has been converted to an unscoped enum. This can result in compilation issues if implicit conversion between an int and google::LogSeverity was erroneously assumed.
• A lot of fixes and enhancements (see full changelog)

Code changes

At this update we need to fix our codebase to have full comparability with this and futures release of glog. Thanks @torwig for this fixes.

• Fix google::EnableLogCleaner (done)
• Fix linting and code checks (done)
• Fix google::LogSeverity (done)
• Fix a symbolizes a program counter (in progress)

[aleksraiden]

Now we have unresolved issue at build kvrocks:

[100%] Linking CXX executable kvrocks
/usr/sbin/ld: CMakeFiles/kvrocks.dir/src/cli/main.cc.o: in function SegvHandler': /__w/kvrocks/kvrocks/src/cli/signal_util.h:54:(.text.SegvHandler[SegvHandler]+0x266): undefined reference to google::Symbolize(void*, char*, unsigned long)'
collect2: error: ld returned 1 exit status

[torwig]

google::Symbolize isn't exported anymore in 0.7.0 so we need to use something else for our purposes (or ask the maintainers of GLOG to export it again :) ).