Fixed silly type-conversion bugs I introduced, added -Wconversion to

makefile.unix to catch these problems sooner.

git-svn-id: https://crawl-ref.svn.sourceforge.net/svnroot/crawl-ref/trunk@1513 c06c8d41-db1a-0410-9941-cceddc491573

Created by  dshaligram  on June 2, 2007
LVP5I5DHJGY3DG3DLIYBDVNULBCM7CD3HF4E5DW5QHCM6P2UZEJQC
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