alphabet2kana bug

[Cuddlemuffin007]

1. su is converted before tsu leading to words like 'atsui' being converted to 「あっすい」
2. Trailing oh is converted too soon leaving words like 'itoh' as 「いっおお」
3. Remaining oh replacements should be done after other replacements, current placement causes words like toho to become 「っおおお」
4. singular m remains unconverted and becomes 「っ」, e.g., namba => なっば
5. dzu is not converted, e.g. tsudsuku => っすっずく

>>> from jaconv import alphabet2kana as a2k
>>> a2k('tsudzuku')
'っすっずく'
>>> a2k('namba')
'なっば'
>>> a2k('itoh')
'いっおお'
>>> a2k('toho')
'っおおお'