tweaks: fold some regexes into one another, for conciseness

The anchored "^texture" appears to have been a mistake.
Inspired-by: Tom Levy <tomlevy93@gmail.com>

syntax/go.nanorc

@@ -24,13 +24,9 @@ color brightcyan "\<(package|import)\>"
 color brightcyan "//[[:space:]]*\+build[[:space:]]+(([a-zA-Z_0-9]+[[:space:]]*)+,[[:space:]]*)*[a-zA-Z_0-9]+"
 
 # Literals.
-color red "\<[0-9]+\.[0-9]*([Ee][+-]?[0-9]+)?i?\>"
-color red "\<[0-9]+[Ee][+-]?[0-9]+i?\>"
+color red "\<[0-9]+(\.[0-9]*)?([Ee][+-]?[0-9]+)?i?\>"
 color red "\B\.[0-9]+([Ee][+-]?[0-9]+)?i?\>"
-color red "\<[0-9]+i\>"
-color red "\<[1-9][0-9]*\>"
-color red "\<0[0-7]*\>"
-icolor red "\<0x[0-9a-f]+\>"
+color red "\<(0[0-7]*|[1-9][0-9]*|0[xX][0-9a-fA-F]+)\>"
 
 # Strings and characters; slightly fuzzy.
 color red "\<(true|false|nil|iota|_)\>"

syntax/pov.nanorc

@@ -7,9 +7,7 @@ color brightcyan "^[[:space:]]*#[[:space:]]*(declare)"
 color brightyellow "\<(sphere|cylinder|translate|matrix|rotate|scale)\>"
 color brightyellow "\<(orthographic|location|up|right|direction|clipped_by)\>"
 color brightyellow "\<(fog_type|fog_offset|fog_alt|rgb|distance|transform)\>"
-color brightred "^texture\>"
-color brightred "\<(light_source|background)\>"
-color brightred "\<(fog|object|camera)\>"
+color brightred "\<(background|camera|fog|light_source|object|texture)\>"
 color green "(\{|\}|\(|\)|\;|\]|\[|`|\\|\$|<|>|!|=|&|\|)"
 color brightmagenta "\<(union|group|subgroup)\>"