v2.1.1: version: bump patch number

Bug fixes:

• LTO fixes
• fix build with latest XED
• fix section locking error on file map failure on Windows
• update modrm and immediate tables from latest XED
• fix opcode space for VEX and EVEX
• fix a pttc internal error
• fix ptxed --check

v2.1

New features:

• a new tool 'ptseg' for finding the PSB segment for a given offset.
• a new layer 'evt' representing the trace as a list of events.
• event tracing (cfe and evd packets).
• C11 threads, if available.

Bug fixes and support for latest processors.