Remove Simplified-Traditional cross mapping code

Removed some Simplified-Tranditional cross mapping Cangjie 3 code.

These are the Cangjie 3 cross-mapping code found in the common range (big5 and hkscs):

| Character | Code  | Supposed Mapping Logic                           |
| --------- | ----- | ------------------------------------------------ |
| 後        | hmr   | Code belongs to "后" (Simplified variant of it)  |
| 后        | hovie | Code belongs to "後" (Traditional variant of it) |
| 祢        | ifmfb | Code belongs to "禰" (Traditional variant of it) |
| 虮        | livii | Code belongs to "蟣" (Traditional variant of it) |
| 玺        | mbmgi | Code belongs to "璽" (Traditional variant of it) |
| 覇        | mbtjb | Code belongs to "霸" (Traditional variant of it) |
| 虬        | livl  | Code belongs to "虯" (Traditional variant of it) |
| 漱        | edlk  | Code belongs to "潄" (Traditional variant of it) |

Since these are not the direct Cangjie code to the character, they are removed.

Should fix #81.

Note:
1. Traditional-to-Simplified is already handled in pull request #69.
2. Simplified-to-Traditional is not considered feature to libcangjie's target users.
Fixed a few Cangjie 3 code

| Character | Code  | Judgement                                                                   |
| --------- | ----- | --------------------------------------------------------------------------- |
| 䱽        | nfomr | "倉" is "oiar". Should be "oir" on right side. Therefore should be "nfoir". |
| 凢        | hn    | The references show a separated slash on top. Should be "hhn".              |
| 厮        | itcl  | There is no "、" on top. Should be "mtcl".                                  |
| 疴        | knlr  | Could be typo for "n" that should be "m".                                   |
| 葱        | tphp  | Should be mixing up "勿" with "匆"                                          |
| 袖        | iflw  | "礻" is mapped to "if" while "衤" is mapped to "l". Strange addition        |
added gentoo instructions
Merge pull request #87 from brendanhoran/master

added gentoo instructions
Merge pull request #85

WTF happened here?

This is marked on github.com as having been merged back in April!

And yet, it clearly never was merged. o_O