Move all lua related files to lua/ subfolder

Also remove the lexers sub directory from the Lua search path.
As a result we attempt to open fewer files during startup:

 $ strace -e open -o log ./vis +q config.h && wc -l log

In order to avoid having to modifiy all lexers which `require('lexer')`
we instead place a symlink in the top level directory.

 $ ./configure --disable-lua
 $ rm -rf lua

Should result in a source tree with most lua specifc functionality
removed.

1 files changed, 0 insertions, 44 deletions

diff --git a/lexers/diff.lua b/lexers/diff.lua
deleted file mode 100644
index 9bc63f1..0000000
--- a/lexers/diff.lua
+++ /dev/null
@@ -1,44 +0,0 @@
--- Copyright 2006-2016 Mitchell mitchell.att.foicica.com. See LICENSE.
--- Diff LPeg lexer.
-
-local l = require('lexer')
-local token, word_match = l.token, l.word_match
-local P, R, S = lpeg.P, lpeg.R, lpeg.S
-
-local M = {_NAME = 'diff'}
-
--- Text, separators, and file headers.
-local index = token(l.COMMENT, 'Index: ' * l.any^0 * P(-1))
-local separator = token(l.COMMENT, ('---' + P('*')^4 + P('=')^1) * l.space^0 *
-                                   -1)
-local header = token('header', (P('*** ') + '--- ' + '+++ ') * l.any^1)
-
--- Location.
-local location = token(l.NUMBER, ('@@' + l.digit^1 + '****') * l.any^1)
-
--- Additions, deletions, and changes.
-local addition = token('addition', S('>+') * l.any^0)
-local deletion = token('deletion', S('<-') * l.any^0)
-local change   = token('change', '! ' * l.any^0)
-
-M._rules = {
-  {'index', index},
-  {'separator', separator},
-  {'header', header},
-  {'location', location},
-  {'addition', addition},
-  {'deletion', deletion},
-  {'change', change},
-  {'any_line', token('default', l.any^1)},
-}
-
-M._tokenstyles = {
-  header = l.STYLE_COMMENT,
-  addition = 'fore:green',
-  deletion = 'fore:red',
-  change = 'fore:yellow',
-}
-
-M._LEXBYLINE = true
-
-return M