Add =shlibs-added/=shlibs-removed notifications (MI)

Summary:
This patch adds =shlibs-added/=shlibs-removed notifications in lldb-mi. In more detail:
# Add Target::ModulesDidLoad/ModulesDidUnload notifications
# Improve Target::TargetEventData:
## Refactoring
## Move it back to include/lldb/Target/Target.h
## Add Target::{GetModuleListFromEvent,GetModuleList}; Add Target::m_module_list
# Add SBModule::{GetSymbolVendorMainFileSpec,GetObjectFileHeaderAddress}
# Add SBTarget::{EventIsTaretEvent,GetTargetFromEvent,GetNumModulesFromEvent,GetModuleAtIndexFromEvent}

All tests pass on OS X.

Reviewers: abidh, zturner, jingham, clayborg

Reviewed By: clayborg

Subscribers: jingham, zturner, lldb-commits, clayborg, abidh

Differential Revision: http://reviews.llvm.org/D8201

llvm-svn: 231858