fix(bin/linja): add 'all' to phony target; allow multiple phony targets
fix(shell/lean.cpp): print git commit in version string only when it's available
feat(src): add LEAN_VERSION_PATCH
chore(CMakeLists.txt): standard_lib target generates TAGS for library
fix(CMakeLists.txt): rename EMACS_LIB to EMACS_LISP_DIR (default: share/eamcs/site-lisp/lean)
feat(CMakeLists.txt): install lean library to LIBRARY_DIR (default: lib/lean)
fix(bin): use "python" instead of "python2" or "python2.7"
feat(util/lean_path.cpp): add "exe_path/../lib/lean" to LEAN_PATH

Related issue: #223
fix(emacs): support tabs in a file

Fix #226
fix(bin/ltags): add option --relative to handle path relatively

Fix #230
fix(frontends/lean/elaborator): 'as-is' expressions

The elaborator should not introduce implicit arguments on terms marked
as 'as-is'.
refactor(kernel/macro_definition_cell): improve macro get_type API