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, 49 deletions

diff --git a/lexers/README.md b/lexers/README.md
deleted file mode 100644
index 6e43e94..0000000
--- a/lexers/README.md
+++ /dev/null
@@ -1,49 +0,0 @@
-Lua LPeg lexers for vis
-=======================
-
-Vis reuses the [Lua](http://www.lua.org/) [LPeg](http://www.inf.puc-rio.br/~roberto/lpeg/)
-based lexers from the [Scintillua](http://foicica.com/scintillua/) project.
-
-# Vis integration
-
-Vis searches the lexers in the following locations:
-
- * `$VIS_PATH/lexers`
- * `./lexers` relative to the binary location (using `/proc/self/exe`)
- * `$XDG_CONFIG_HOME/vis/lexers`
- * `/usr/local/share/vis/lexers`
- * `/usr/share/vis/lexers`
- * `package.path` (standard lua search path)
-
-at runtime a specific lexer can be loded by means of `:set syntax <name>`
-where `<name>` corresponds to the filename without the `.lua` extension.
-
-# Adding new lexers
-
-To add a new lexer, start with the `template.txt` found in this directory
-or a lexer of a similiar language. Read the 
-[lexer module documentation](http://foicica.com/scintillua/api.html#lexer).
-The [LPeg](http://www.inf.puc-rio.br/~roberto/lpeg/) introduction might also
-be useful.
-
-For development purposes it is recommended to test the lexers from a lua
-script as described in the
-[Scintillua manual](http://foicica.com/scintillua/manual.html#Using.Scintillua.as.a.Lua.Library).
-
-To enable auto syntax highlighting when opening a file you can associate your
-new lexer with a set of file extensions by adding a corresponding entry into
-the table found at the end of the [vis.lua](/vis.lua) file.
-
-Changes to existing lexers should also be sent upstream for consideration.
-
-# Color Themes
-
-The `themes` sub directory contains the color schemes. At startup the
-`default.lua` theme which should be a symlink to your prefered style is
-used. Themes can be changed at runtime via the `:set theme <name>`
-command where `<name>` does not include the `.lua` file extension.
-
-# Dependencies
-
- * [Lua](http://www.lua.org/) 5.1 or greater
- * [LPeg](http://www.inf.puc-rio.br/~roberto/lpeg/) 0.12 or greater